The first thing you want to do is get someone out there to see if they can determine the cause of the leak. It may be the roof, it may be missing gutters, it may be from water sticking around from a clogged downspout, it may be from ice damming, who knows. Tell the contractor when you see water. (After a rain, when snow melts, etc., etc..) Then, get an estimate. THEN, have 2 more contractors come out to do the same. Don't tell them what you know UNTIL you talk to all 3 of them. Then, call them back, whichever ones you want, and talk about it. Better yet, maybe you can go visit them.
Put the budget aside for now until you know the cause and what it will take to fix the problem. If it's beyond your budget, you have a choice of living with the problem until more $$$ arrives, or you (or someone or family) can help her out. My best to ya and hope this helps.