"if it's what the law says then we might as well make some adjustments and accept it."
Oh I thought of one thing which don't erase the problem, but PERHAPS reduce it. Someone with more skill in inheritance laws can tell if the idea is any useful.
When your mother died, I suppouse you and your sibblings have some INHERIT rights (although your father keep the control and use right).
IF so, I believe ithe part belonging to your father is only a litle more than HALF, so if so the stepmpther can only get her inherit part of that a bit more than half... =The problem is perhaps a bit more than half.
But I don't know if the stepmother keep the control and use right after your father die. That need to be checked.
OR you TRY to get the other solution I wrote about earlier = When you pay the loan, the property is SOLD to you (for the loan money plus difference in value, which can be a loan to them, if they agree to that.) But ot can be hard to convince your stepmother. Start with inform her her share will be only a bit over 1/4 of /the property value MINUS the dept (1/4)./ Perhaps you can make the stepmother sign the documents if you pay her some cash.
" I asked my dad and he said it's named after my mom with the title certificate T 93.467,. Area 189.. Do land titles really present like that?"
According to the bad copies I have seen, it's like that.
" is it still possible for my deceased mom to own it under her name?"
Such is COMMON in the Philippines. It's even common with titles in grandparents name or even earlier, which often make a mess when someone need to check who is owner now. That can be a reason too, you try to buy out them, so you get the title in YOUR name now.
Think of the DIFFERENCE moving it to your name make concerning property tax and bills responcibility, when you discus how much is fair when counting compensation.