Am I really going to be a bad mother 😔

My husbands kids are over for the weekend! And the little girl is nearly 4 and refuses to eat her food instead when's she's at home her mother gives her chocolate for an easy life!! Tonight she refused her pizza and made a massive fuss about it and cried all night! When it came to having a small bowl of ice cream I refused her because she wouldn't eat her food! Now me and my husband has had a argument and keep saying when that one pops out you'll understand how crap I feel and stuff!! Thank you for that like!! Made me feel like crap for standing my ground and he's turning into a wet blanket and wanting to give in!! I've decided to sit upstairs for the rest of the night because I hate arguing in front of his kids but he seems different when he's with them!!!! I just need a rant!!