So my mother has 200k caveat on the house.
Ummmm..... I am slow to use the term "caveat" for what you have done here.
In order for there to be a caveat on the property, she needs to have what the law calls a "caveatable interest".
She may or may not have one, depending on structure of the deal.
Bear in mind also that she and/or you may have used the term incorrectly as you were setting things up.
Caveats themselves don't create charges over land (People often get this wrong. I blame American TV)
Depending on how you set it up, she might have a security interest (for example, if she is a morgtagee), or
she might have an equitable interest (such as if the loan secured by some other form of interest in the property, such as a share of any proceeds of a future sale), or
she might have a part share of the property itself (as say, a tenant in common), or
she might simply be somebody to whom you personally owe an unsecured two hundred thousand dollars.
What you do next depends on the nature of the agreement.
If you want to know if there is, in fact, a caveat on the property, do a title search (or have the lawyer assisting your family law matter, do it).