Hi mattress question,
While I can certainly help with “how” to choose … It’s not possible to make specific suggestions or recommendations for either a mattress, manufacturers/retailers, or combinations of materials or components because the first “rule” of mattress shopping is to always remember that you (or in this case your mother) are the only one that can feel what you feel on a mattress and there are too many unknowns, variables, and personal preferences involved that are unique to each person to use a formula or for anyone to be able to predict or make a specific suggestion or recommendation about which mattress or combination of materials and components or which type of mattress would be the best “match” for you in terms of “comfort”, firmness, or PPP (Posture and alignment, Pressure relief, and your own Personal preferences) or how a mattress will “feel” to you or compare to another mattress based on specs (either hers or a mattress), sleeping positions, health conditions, or “theory at a distance” that can possibly be more reliable than careful testing (hopefully using the testing guidelines in step 4 of the tutorial) or her own personal sleeping experience (see mattress firmness/comfort levels in post #2 here).
I’m not sure what you’ve read since you found the site but just in case you haven’t read it yet … the first place to start your research is the mattress shopping tutorial here which includes all the basic information, steps, and guidelines that can help you make the best possible choice … and perhaps more importantly know how and why to avoid the worst ones.
Two of the most important links in the tutorial that I would especially make sure you’ve read are post #2 here which has more about the different ways to choose a suitable mattress (either locally or online) that is the best “match” for her in terms of “comfort”, firmness, and PPP that can help you assess and minimize the risks of making a choice that doesn’t turn out as well as you hoped for and post #13 here which has more about the most important parts of the “value” of a mattress purchase which can help you make more meaningful quality/value comparisons between mattresses in terms of suitability (how well she will sleep), durability (how long she will sleep well), and the overall value of a mattress compared to your other finalists based on all the parts of your personal value equation that are most important to you (including the price of course and the options you have available after a purchase if your choice doesn’t turn out as well as you hoped for).
Assuming that the materials in a mattress you are considering are durable enough for your body type and meet the durability guidelines here relative to her weight/BMI range … the choice between different types and combinations of materials and components or different types of mattresses are more of a preference and a budget choice than a “better/worse” choice (see this article). Different people just prefer different types of materials or mattresses but the only way to know which types of materials or mattresses or firmness levels she may tend to prefer in very general terms will be based on her own local testing or her own personal experience.
I would also keep in mind that each mattress category can include hundreds of different mattresses with a very wide range of different designs, different “feels”, different characteristics, and different firmness levels. Individual layers and components in a mattress (including the cover and any quilting material) can vary widely with different thicknesses and different firmnesses and every difference will affect the feel and response of every other layer and component both above and below it and the mattress “as a whole” so each mattress category will generally include some mattresses that have an overall design that will be a good “match” for her in terms of “comfort”, firmness, and PPP (Posture and alignment, Pressure relief, and your own Personal preferences) and others that use the same type of materials and components and are in the same category and may be just as durable but have a different design or firmness level that may be completely unsuitable for here to sleep on … even if it uses the same general type of materials and components.
If you are considering online options then the mattress shopping tutorial includes several links to lists of many of the better online options I’m aware of (in the optional online step) that include many different types and categories of mattresses (see this article) that use different materials and components in a wide range of designs, budgets, firmness levels, and with different return/exchange policies that may be well worth considering.
If you are interested in local options then if you let me know your city or zip code I’d be happy to let you know about the better options or possibilities I’m aware of in your area.
I don’t keep a record of the individual mattresses or components or their specs (or thickness) that the retailers and manufacturers in the hundreds of local or online forum lists throughout the forum carry on their floor or have available online (it would be a bigger job than anyone could keep up with in a constantly changing market) but checking their websites and especially making some preliminary phone calls to the retailers/manufacturers that are on the lists that you are considering is always a good idea before you decide on which retailers or manufacturers you wish to deal with or visit anyway. This will tell you which of them carry mattresses or components that would meet your specific criteria, are fully transparent about the materials and components and/or the mattresses that they sell, and that carry the type of mattresses or components that you are interested in that are also in the budget range you are comfortable with. Once you have checked their websites and/or talked with the ones that interest you then you will be in a much better position to decide on the ones (if any) that you are most interested in considering or visiting based on the results of your preliminary research and conversations.
While I have no way to know which types of materials or mattresses she may tend to prefer … if you are limited to 6" then it may be worth considering a 6" latex mattress with either a single 6" layer of latex or two 3" layers of latex because latex is a somewhat unique material that is very point elastic and resilient and can contour well to the shape of the body and in the right firmness levels can be soft and pressure relieving and supportive at the same time even with a thinner mattress. Because of the resilience of latex it is also less motion restricting than other slower responding materials such as memory foam which can make it easier to more or change positions on a mattress than less resilient materials which may be important to elderly people but of course not all people like the “feel” and response and resilience (springiness) of latex.
Phoenix