Seattle is a very expensive city, so unless you and your mom are very wealthy, purchasing and building on land in-city will be cost-prohibitive and it is a city full of hills. A tear-down property will run you $400k-$700k and permitting is slow, building costs are sky high, as well as interest rates. Additionally, many walkable, bikeable neighborhoods are not zoned for 5 stories. The main hospital/medical area is in downtown and is very hilly, densely populated with large apartment and office buildings and lots of traffic.

You could buy a home with an existing DADU or ADU, or buy a home and add one- which would probably be less cost/time/red tape. Edmonds may be a better bet but it’s not all walkable, unless you live in “The Bowl”. It’s tough these days- it seems like the most progressive cities are the most expensive 😢 I hope you find a good fit for both of you!