I sounds to me like you do not want to break all ties with her yet want to bring things into a more normal and controllable relationship. After all you feel that since she is on bed rest you would like to do some form of chesed for her and feel some sense of obligation to her because you do have hakaros hatov for her help and chesed to you in the past.
Maybe you should consider prioritizing your schedules both for yourself and your daughter and include some chesed hours which you can use to help this friend. Then let her know when either you and your daughter would be available to assist her, and even give her the calendar for the week or month and suggest to her that she get other volunteers to fill in other spots so that she will know who she can call on or depend on at any given time. It can also be a very visual and helpful tool for her husband and children to see when she has help and when she doesn’t so they know full well when THEY need to pitch in and do their part.
Maybe we each need to understand that while she goes through her nisayon (whatever it is, you didn’t say) you might be going through your own test as well. So how will you deal with it? Will you resentfully do “chesed” that you don’t want to do, or will you be honest with yourself and make the appropriate changes to do chesed appropriately?