How can I treat a friend whose always treating everyone else?

I have a very close friend - who is painfully kind. She likes her space but is always trying to please and help others. She always wants people she loves to be happy. She is family orientated and has a boyfriend - that's all she needs to be happy. She runs after their every beck and call. I went around her house today and she was discussing going on holiday with her dad and then going away with her mum. While making her sister laugh and doing her other sisters make-up for an evening out. At the same time she was calling her boyfriend to wake him up - as he had asked her to. She even was trying to arrange a manicure with me - at the same time! How to I get her to take it easy and worry about herself sometimes? I think it's great that she's so selfless, but I want to do something nice for her in return. Any ideas?