Your question is a bit complicated,
If you want to contact me privately I can discuss
possible options with you. I’m Realtor & mortgage guy.
YOU cannot borrow money on your mother’s houses.
(Perhaps she can if she qualifies)
If you are a salaried employee, you get no extra credit for being at a job for 10 years, in many cases 30 days is enough.
If your MID credit score is 740 or above, in most cases it makes no difference if your credit score is 760, 800 or 840.
It’s all about qualifying and understanding what it takes to qualify.
In many cases it’s easier for someone with 3% down to qualify than someone who is putting 50% down.
The system is broken and it’s not going to change anytime soon.