In general, room and board payments are not exempt from gift tax accounting, unlike tuition. That is important for grandparents or uncles/aunts who help with college to know. Payments for room and board would be considered gifts either to the student or to the student’s parents (if they have an obligation to support the student, and the relative’s payments reduce that support obligation). It is also important to know that to take advantage of the tuition exclusion, the person providing the funds must pay them directly to the college. If a student’s grandparents give the student’s parents, or the student him- or herself, money to pay for the student’s tuition, that is a gift that has to be accounted for if all gifts the same year to the same person(s) exceed the annual exclusion.
In the case of parents paying paying room and board costs, however, it may or may not be a “gift” for gift tax purposes. In some states, parents have an obligation to support their children while they remain full-time students, and in other states such an obligation may arise pursuant to a divorce decree or an agreement between non-divorced parents. Room and board are core support obligations. So financing room and board, if it satisfies a legal support obligation, would not be considered an accountable gift, and would not count towards the annual exclusion.
As a practical matter, I have never heard of the IRS going after parents for supporting their college students, even if there is no technical support obligation in their state. Doing so would (a) be very unpopular, politically and socially, (b) force a whole lot of people who would never expect to pay a cent of gift tax or estate tax to file gift tax returns, and © raise serious equity considerations because of state-to-state differences in precise support obligations.
Also, to answer the OP’s question: Not only can you and your husband file separate gift tax returns while you are married, you must file separate gift tax returns if both of you are required to file. There is no such thing as a joint gift tax return. What there is, is an election whereby a married couple can choose to treat all gifts made by one of them as gifts made by both of them in equal shares, but both members of the couple must agree to that specifically, and if they do that, then both have to file their separate gift tax returns even if only one of them actually made any gifts over the annual exclusion limit for both. One advantage of making that election, however, is that it effectively doubles the annual exclusion for a gift to one person. If your then-husband gave his mother $25,000, that would mean an $11,000 gift that had to be reported. But if you and your then-husband elect to split your gifts that year, and you had not separately given anything to your ex-mother-in-law, then the entire $25,000 would be covered by your combined $28,000 annual exclusion. That alone wouldn’t have any negative effect on you as long as you hadn’t given your ex-mother-in-law more than $3,000 yourself.