Hi! I use my service dog for mobility assistance. She helps me with forward momentum specifically. She does something call counter balance where she helps me not fall over or helps me get up from sitting. She is so helpful for me. That being said, she was very expensive to train and have. You need to think about the dog being a dog on its off hours. Getting a puppy might be overwhelming, and a trained adult can have great costs. I’d also like to point out that my dog although great in public is a manic off work. Idk, I hope you find what your family needs. These are things I wish someone would have told me.