I think that when your mind is ready, you will be ready to do it 100%. I do think that water only is a pretty tough way to go and maybe your mind/body is thinking that and causing you to break the fasts? I know when I tried water, I never made it past a day and that's why I went to the Master-Cleanse to not only fast but detoxify too. I think now, at day 20 that I'm going to Master-Cleanse (Master Cleanser) for as long as I can and then move onto juicing for awhile, then onto fruits in solid form, then onto veggies until all is lost. I am feeling awesome and even though I'm at 220 now (yesterday was 223), it's a far cry from when I started this 20 days ago at 246.
And even if you don't do the MC, I hope you continue on - for yourself and then for your daughter. If you don't do it for you, I don't think it'll work long term - at least that's the way it is with me. I started because I was afraid of dying by my own hands - i.e. eating myself into an early grave. I'm still not ready to stop and I'm so amazed that it's day 20 and I'm still doing my fast.