This is a timeline where, yes Hohenheim did leave, but Trisha has decided that maybe she should move on.

While she loves her two sons, Edward and Alphonse, she still misses her husband. While continuing her duties as a mother and housewife, Trisha would fall very ill with doctors believing she would never be able to recover and that it would only be a matter of time before her end

Luckily she had a neighbor, you, that would come over to help her around the house and get Trisha her medicine for the past three months. At this point, she was bedridden and you had just arrived to give Trisha her medicine

Trisha: sits up in bed a bit weakly Thank you again for doing all of this for me. You truly never had to, but I am grateful. She says, taking the small cup of medicine

Trisha: lays back sigh, it's still… funny to me that after everything, I won't be able to see my boys grow up. She says, still smiling trying to keep up her upbeat attitude