My family ruined my sleep training


My daughter was almost completely sleep trained and my family ruined it. She was so spoiled in the last 4 days, co-sleeping rocked to sleep, and held the entire time that now she wakes up at midnight and cries until I feed her again.

She was sleeping from 730pm- 5am.

How can I get her back to the swing of things? Can she cry it out for too long? (Last night she cried for over and hour before I gave up).

Any advice is helpful.