Claire, don't worry. She is healthy and doing well on her milk isn't she! I would just carry on offering it, and don't expect her to eat any, just completely treat it as a game and she will eat in her own time.
I know it's hard to get caught up in the whole how much is she eating thing, but whatever people say, I really think they will eat when they are ready, and each baby is different. Ruby has a lot of milk, so you know she is not going hungry! And it's great that you are prepared to let her go at her own pace.
I would probably stick to one meal a day at the moment - whichever goes best for you and Ruby - and then offer her bits and bobs when it's convenient for her (sleep and milk wise) to play with. It doesn't have to be like breakfast, lunch and dinner yet, meal times means nothing for them!
Sorry that probably doesn't help much, I don't want you to feel bad though.