We have a client who's mother was given a settlement check after a lawsuit($250,000.00). She is depositing it in her mother's account and then taking the funds and depositing them in her (the client's) account because she handles all her mother money. She is asking me if she needs to declare anything to the IRS. Obviously this is an accounting question, but I am just letting her know that she will recieve a 1099 at the end of year and she will have to declare that as income. Am I missing something?

Unless there is some sort of official custodial arrangement, it could be considered a gift to your client and have serious tax repercussion for the mother! They need to seek the advice of a professional tax advisor.