Don’t you think my cousin is making a big mistake on marrying a man like 13 years older then her?

I personally don’t agree with their age gap and dating but I’m happy for her no matter. My cousin is 31 and her fiancé is 44. He already has two kids from his previous marriage (16 and 12). I mean they’re an amazing couple. I told my cousins it was kind of weird of something that is 40 something years old and it’s bad enough. They looked shocked of what I said. My brother said, “Oh come on. It’s not THAT bad. They’re both adults so they’re in love and that’s all that matters.”
But I said, “I don’t know. It’s still weird. She should date someone her own age.” My sister said, “It’s not weird (my name). Don’t be so judgmental. It’s okay to have an opinion, but they don’t care about your opinion and you need to just be happy for them.”
I was angry that they didn’t agree with me. 44 is too old for a 31 year old woman!