Sleep regression

Mary • Hello my names mary im 33 my husband is 38 we have been married since this july 2015 been together since april of 08 we have two beautiful daughters ages 15 and 7 and s sob thsts 4

Anyone’s 2 year olds go to sleep fine by their selfs and all of a sudden cry and scream and fight to sleep till you rock them to sleep? Idk why it’s happening all of a sudden