Empathise/sympathize with her and assure her that you will continue to use her services but beyond that, you cannot help further unless you want to or can as Minime said! Many ladies with kids are struggling and you can't blame her for trying! Mothers will do anything for their kids. If you stop seeing her because of this, you make her situation worse! Yes, it's not your problem but if you give it to her straight, I'm sure she'd understand. If she starts to act differently after you tell her, then it's probably best to move on!

If you want to help, then do that if you feel that in your heart, and if you can afford to donate the money. Its a lesson life has taught me. If you want to give money, and you can afford to donate and not need it back, then do it. If I can't afford to give it then I won't lend it or advance it on some promise made.