Should I fix foundation before renovating?

[Kevin Yang]

I have a property that I bought for my mom to live in because she is retired. The house was built in 1930s so pretty old but has no water leaks or anything like that in the basement. We have been living (was renting) in this home for over 20 years and now I own it. I bought it for my mom to live in but if for any reason one day she moves out, it would become a rental property. I want it to be a safe home for her and so I would like to upkeep it to the best of my ability but still being cognizant that it's not a rental yet. Everything in the home is original and nothing has really been renovated since we've lived there, so you could imagine all the renovations there are to be done. There is still the original old vinyl sticky kitchen flooring that is wavy and uneven and original countertops. Would you fix the foundation before doing any renovations (new flooring, countertops, appliances) if the floor is wavy and uneven? I had a couple contractors come quote me on foundation and it would cost 10-15k to "level" the first floor. This is my first rental-ish and I'm wondering if it'll be worth fixing foundation first before renovating. 

Any input will be greatly appreciated!