I'm searching for my wife a replacement mountain bike for rails to trails riding.. she has verbally stated she prefers a bike that doesnt have the seat higher than the handle bars.. the old bike which i'm switching around to give to my 15 year old.. is actually a schwinn from 1990 or so.. still in great shape.. rigid mountain bike.. the seat probably is slightly lower than the handle bars as is right now.. whereas say my schwinn from 2001 is probably even with the handle bars.. both of these 26" rigid.. neither has suspension or anything more modern (heavier older mountain bikes) with say 1.75-1.95" wide tires, nothing too wide as we dont go off trail that much.

Despite what she is after here .. i'm wondering what is considered more the norm.. or what type of bike ideally to strive for.. either way its on a budget.. hoping for a used one or maybe a budget one new.. under $200.. that limits options.. I think from what i've seen, many are using much bigger size tires now.. 29" to 32".. is this accurate.. does it make it that much easier to go further on a trail i would assume? We typically ride 7 to 20 miles on our 26" bikes.. often pulling our 2 year old in a trailer on one of them.

Any suggestions on what the optimal style bike would be (hopefully with a picture as guide for whats meant by that style)?
Sizing wise.. i'm seeing she should probably be on a 17" bike "size" given 5'8 and 29-30" leg length.. she also complains of every seat i've tried to switch out as hurting too much, but thats another issue (she is thinking wider on the seat in the future perhaps)..

I'm a bit behind in whats new these days .. hoping for some input.

Thanks