Given your responses on here, OP, I think it's best that you don't attend. You've been very unpleasant about your cousin.
You've accused her and her partner of prioritising photos over family, of wanting a Pintrest wedding, of being shallow, of being controlling, of being hurtful and being rigid.
And also that you want to boycott in principle because you don't think they should be allowed to have the kind of wedding they want, because you might find childcare a bind.
Also that your husband could stay with the children and you attend, but you don't want that either. But it's THEM you you say are being rigid and unyielding.
No, OP, you are being rigid. And judgemental. And you're trying to make your cousin's wedding into something that fits your idea of a wedding, not hers.
For her sake, RSPV with a no, send a nice gift, and leave her to have a lovely time with people who are happy to support her choices.