How to transfer from free coaching swaps to paid coaching with the same client

I do The Work of Byron Katie and I currently do a twice weekly “swap” with another facilitator who has also been to the School for The Work. She has been working on her issues around her mother for a long time and recently shared in a Facebook group that she wished she could ‘get to the bottom’ of her mother problems. So I contacted her and I told her that “adult women who have issues with their older mothers” is my coaching niche now and I’d like to offer her some coaching. She immediately said “yes please”, but she has no clue what that would involve. We are having a call today where I will make her an offer.

My challenge is how to start charging “proper money (I charge £1,800 for a programme of 12 weeks) when up until now she has had my support and facilitation twice weekly for free. She has also been facilitating me. My idea is to call a halt to any more ‘free swaps’ now and for me to become her coach for the next 12 weeks. As I haven’t had a paying client for a long time I feel both excited at the prospect of helping her resolve her mother issues (I know how to do that) but I also feel awkward as we are friends now and it feels like I should maybe make her a special offer (?) Any help would be gratefully received.