WIBTA for asking my 50 year old sister what she does with her money before giving her another $100?

Hello Reddit,

My older sister is almost 51, has a husband who only works on the weekends and a 19 year old son who doesn’t have a job. They all live with her husbands mom since the early fall since they “moved” out of their leased house (that’s another story). My sister only contacts me when she needs cash.

I moved out of my home town when I went to college and never moved back after graduating, I now live across the country from them and go home to visit every year.

I know my parents gave her well over $10K about a month ago to help her find a new place to live b/c her mother in law wants them out of the house. So far, they have not moved out, nor from what I can gather talking to my mom have made any progress in finding a place to live. This morning my sister hits me up for cash promising she will pay me back next week ( over the years she has never repaid me once).

Thankfully my family and I live comfortably and giving her the cash will not create problems for us. I just want to know if I would be the asshole for asking her what exactly she does with her money each month? From my perspective, they live rent free (if not, I am sure here mother in law is not charging fair market value to live with her) and I know she has (maybe now it should be “had” the money my parents gave her). At this point, my parents (to a greater extent) and I have given her tens of thousands of dollars over the years and never seen a dime. Her husband refuses to get another job and I don’t know why her son won’t get a job as well since he has been out of school now for quite some time.

Personally, I do carry some guilt for moving away to build my own life and shouldering her with the responsibility of taking care of our aging parents. While both of my parents are fully capable of taking care of themselves and still live fulfilling lives, I know eventually that will change and I am not in a position to move back to my hometown due to my military career.

I just need a forum to vent and solicit advice. Thanks everyone for listening!