Hi kc12,
I certainly get asked very similar questions every day but I’m always happy to answer them 
My reply would be the same as my reply in post #2 here (after the “HELP? Suggestions?” quote).
You can see some comments about Saatva in post #2 here and the posts it links to that I would make sure you read before considering a Saatva mattress.
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.
An innerspring isn’t normally the weakest link in a mattress and the durability and useful life of an innerspring mattress will depend much more on the quality and durability of the materials or components that are on top of the innerspring than on the innerspring itself. If the innerspring in a mattress is firm enough to keep you in good alignment and a mattress “as a whole” is a good match for you in terms of comfort, firmness, and PPP (Posture and alignment, Pressure relief, and your own Personal preferences) then it’s very unlikely that an innerspring would be an issue in terms of durability.
Subject to first confirming that any retailer or manufacturer on the list that you wish to visit is completely transparent (see this article) and to making sure that any mattress you are considering meets your criteria and the quality/value guidelines I linked earlier in this reply … the better options or possibilities I’m aware of in and around the Lubbock area are listed in post #2 here.
Phoenix