AITA for not giving my mom money?

My mom has a habit of asking me (29F) for money and it has been this way for years now. She is employed, owns her home with no mortgage and makes enough that she should be able to live comfortably as she doesn’t have housing expenses. The reason why she never has any money is because she’s supporting my brother (25M) who doesn’t work and doesn’t have any post high school training/education. He lives with her and from my understanding he spends all her money on his car, car insurance, legal expenses from DUIs, DoorDash, fast food and gambling. She allows him to use her money for these purposes to keep him happy. I tell her to kick him out of her house.

When my mom doesn’t have any more money she starts calling me and says she needs grocery or gas money for herself but I know the money will just go to my brother. I have given my mom some money in the past but I can no longer do so as my husband and I are trying to buy a house and are trying for our first child. She doesn’t ask for a little bit of money, sometimes 200-500 at a time and asks sometimes 2-3 times a week.

Now my mom has lost her job and needs some money to get by on but I told her no. My husband and I are trying to have a baby and purchase our first home and giving her money is causing problems in our marriage. AITA?