My nieces constantly prey on their grandmother for her for money.

I dont' know how old your nieces' are but they shouldn't be taking advantage of their grandmother. Are the parents' aware of what they are doing? This is something that should be discussed with the parents, they probably dont' know what is going on or if they do they are being quiet about it. You know them best. Your mother has worked hard for her money and it shouldn't just be handed out. If your nieces' are able to help your mother in some way shape or form and she herself wants to pay them, then thats different. If they only come around when your not at home they obviously know that it wouldn't happen if you were there. Where did respect for our elders go? They obviously know that grandma will give us money or they wouldn't ask. If it were to help with college or university funds that their parents' cant' afford, then the parents' should be doing the asking, NOT them. I think its high time that you call your sister/brother and tell them that you would like to speak with them away from home. Meaning a coffee shop or elsewhere. Let them know its important for them to meet you but not life threatening. Once you meet up then explain the situation, ask them if they are aware of their children doing this. Make it a friendly conversation, their is no need for arguements, you would just like to know if they know. If they do ask them why it isn't them that is doing the asking. Are they afraid to, and knowing that grandma wouldn't say no to them. They could be in debt themselves and dont' want to say anything for fear of embarrassment, nor do they want to stress grandma with their problems. Dont' be afraid to speak out, if they are short themselves then hey maybe "Mom" could help them out somewhat. You can bring this into the conversation nicely so you know where things stand. On the other hand if they no nothing about it then hopefully they will speak to their children and put a stop to it. I wish you luck, and this will make your mom feel better as well. Either the parents will ask or it will end. This way you wont' have to listen to what happened when you come home to mom and get stressed out. The nieces' may think of you being mean because your telling on them but what if they are asking for money that is being used in the wrong way. This needs your utmost attention.