Need advice, landlord is refusing to fix ac

I’m new to renting a house, I’ve always lived in an apartment and never had this problem before. We’re barely moving in and she had said the ac was working fine, as soon as we got our light connected we checked the ac and it’s not cooling, we had someone come check it and he said the ducts were broken and the whole ac unit needs to be replaced, we let the landlord know and she refuses to change it and it’s telling us to do it ourselves which we don’t have the money to do so right now because it’s in the thousands. I have two little kids (1yr old and 3yrs old) and for sure we can’t be living there without any kind of ac.

Edit: I have text of her stating she won’t take care of it and to do so ourselves, also have pictures of how the ac unit looks.