DD's (9) best friend has become a compulsive liar

[KayKayP]

DD (9) has a best friend (I'll call her "T") who is a bit of a compulsive liar. It is more than just occasional white lies that children (and adults) sometimes tell. It started (around a year ago) as lies about travelling to various places, and I didn't become concerned until I recently became aware that T has been lying about having multiple serious illnesses (including cancer!) and allergies that she does not have. I imagine that T is doing this to get attention and seem more interesting. I'm wondering if I should say anything to the mother because she seems to be oblivious and unaware of her daughter's "habit". I really like the mother and get on with her quite well and do not want to cause drama or make things uncomfortable between us by accusing her child. However, I'm concerned that this could worsen if it's not addressed. Ignoring a problem does not make it go away.

Where is she doing this? When visiting your house? When at school? If she is repeatedly making up lies like having cancer at school I’d have expected school to be talking to mum. It sounds like it’s getting out of hand. If you talk to mum I’d be saying something along the lines of - ‘oh T said the funniest thing last week- she was telling the girls she has cancer’ … find a way to tell her without being accusatory or sounding judgmental. Tricky one.

Don't say anything to the parents, home life might be exactly why she is lying.

She sounds like a very unhappy little girl. Is she doing it at school as well, or just when she's with you?