Tax exempt

I went from being a stay at home mom to to working as a care aide in November of 2024. Prior to November I had no income. I made $5500 total in 2024 but my employer wasn't taking out federal or state taxes so box 1 on my w2 says $0 which has greatly reduced my refund because I can't claim the full child tax credit for my 3 kids. We are in the low income bracket and we heavily rely on our tax refund each year to support our family.