My Mother In Law Has A Large Water Cyst That

My mother in law has a large water cyst that hangs down just like a man's testicle would. She has been struggling to seek help but is very embarrassed about it. The cyst started in between her leg and vigina lip.. it's very large. It's not painful but it's put a damper in your life. The best way to describe it, is it looks like a man's testicle ..shape and feeling..but without hair. Could you tell me what kind of cyst this may be? I have encouraged her to go to the doctor so we are going to go soon