Hi kll4,
There are several reasons why younger children benefit from a firmer mattress. The first of these is that as you mentioned their bodies are not as curvy and they don’t have the same “gaps” that need to be filled in or the same degree of more “protruding” parts that need to sink deeper into the mattress. Their weight distribution, body shape, and overall body makeup in other words are very different from an adult.
The second and most important reason is that they are more flexible and pliable than adults (their skeletal structure is not as rigid as an adult) which means that they are less susceptible to pressure issues and much more susceptible to misalignment issues which can become more permanent over time as they grow and their spinal structure becomes more “fixed”. Their first priority is alignment to help support the best development and alignment of their spine as they grow. Children … especially younger children … can be much more affected by issues that adults have developed some form of “immunity” against (whether this is chemical or structural). This doesn’t mean of course that all children should be sleeping on the floor … only that they will usually do best with firmer layers that would often be uncomfortable for an adult (even a light adult). I would tend to avoid “soft” and focus more on “medium” or higher with either very thin or no comfort layers (which can be added later when they get older). There is enough softness in these for their pressure relief needs unless there is a specific reason (coming from a medical professional) that there needs are different from the norm.
One final issue (and this applies more to younger infants) is that with too much soft material in a mattress … the risk of suffocation with stomach sleeping increases for infants that are not yet able to change position. This is more of an issue with memory foam than other materials (this of course is in addition to any chemical or offgassing issues from synthetic materials that young children may be more sensitive to than adults). I would avoid memory foam for younger children in particular (see post #2 here)
Naturepedic is a high quality and most importantly “safe” mattress which is made specifically with the needs of young children in mind. Their focus is on “safe” materials and they make one of the only two mattresses that are actually GOTS certified as organic (the other being Organicpedic). This doesn’t mean that they are the only company that are using organic materials in their mattresses … only that they are the only ones who have had the entire mattress and production process certified as a unit.
Yes … as you mentioned this would be because of the waterproof ticking (which is also food grade and safe for infants)
While this would not be an issue for the children … it could easily be an issue for the parents that wanted to lie on the mattress with their children. I would go with medium firmness (not the soft 22-24 ILD that is more suitable for adults but more along the lines of mid-high 20’s or low 30’s). While both blended Talalay and 100% natural Dunlop are “safe” materials and would be suitable, for those who prefer all natural materials I would probably lean towards 100% natural Dunlop both because it is more economical and because it can be a little softer on top but gets firmer faster than Talalay. I wouldn’t use more than 2" (1" can be difficult to find in latex). By the time they are older (pre-teen range) then you could change the topper or add a softer layer if it becomes necessary.
While it’s unlikely that you “need” a topper … it may still be useful as a way that you can also be a little more comfortable on the mattress and it may also alleviate the air puffiness. As I mentioned though … I would avoid going too soft and “translating” the needs of a lighter adult into the needs of a younger child.
While this could vary between manufacturers … typically they wouldn’t. If the cover is organic or uses natural materials and is from a reputable manufacturer (that will tell you what they use) then this wouldn’t be an issue. It is important though to use a good quality cover with a latex topper because it will protect it from oxidation and pre-mature degradation.
Hope this helps and if I’ve missed anything let me know.
Phoenix