I don't know what either of you are dealing with, but what I see a lot of is people not putting 20% down, making minimum payments or missing payments, and being terrible with money general. Mortgages can be transferred but requires the lender's approval. As long as the assumer of the mortgage has good credit, it can be done.
My advice is always put 20% down, do not miss payments, and live beneath your means. I see way too many people say it's impossible, but the issue is they basically give up on the idea of saving a little money every month because their dopamine receptors are completely fried. If you cut the cable, you can save an average of $120 a month. Even more if you don't buy streaming services. Don't buy junk food, hang onto old phones, old cars, and so on. Buying a house is possible, but so many people fuck themselves by not caring about their credit early in life and being spendthrifts.