3 year old constantly ignoring me help!!!

Dajuanna • Mommy of a 5 year old girl 👧🏾and a 4 year old boy 👶🏽 and lost my 3 month old due to SIDS

I have a 3 year old girl that constantly ignores me and I have no idea how to correct this behavior and now she has my son following her as well any suggestions on how to fix this cause nothing I'm doing seems to work.