Another Sticky Wicket Question

So my father has an adult female cousin, who is divorced, and has a teenage daughter. She is not seriously seeing anyone. She is still invited 'plus one' to the wedding, because we are assuming that she will bring her daughter. Her brother and sister are just invited with their spouses, not their children, because then it would start to get crazy with the numbers, especially because my father isn't super close with his cousins.

So my mother plans to invite the woman cousin to my shower, with her daughter, by name on the invite.

So then that poses the question, for the wedding invitation, do I invite her with her daughter by name, or '& guest' and leave it to be her choice to bring her or a bf?

But then since the girl is invited to the shower, it's tacky to not invite her to the wedding, teenager or not.

But then I don't want the siblings to be like why is she invited and my kids not? My mother said that they would understand it's extenuating circumstances in this case because she's a single mother with no serious bf or new spouse, and that she does everything with her daughter, but I'm not too sure.

Ahhh! Would you invite a woman in this situation with her daughter by name and screw what the other cousins think about it, or & guest and then offend shower etiquette?

I have this exact situation with a cousin of my dad's. She goes everywhere with her 19 y/o son. Always has.

I'm not inviting any of my dad's other cousin's children to the wedding, but I invited this one with her son. The invitation read:

Dad's Cousin LastName
Her Son LastName

Same on the inner envelope.

In your case, if the cousin wants to bring a guest besides her daughter, she should just call you and tell you, or you can call her or email her to explain that she is welcome to bring someone else, but to let you know, if that's how you want to leave it. Way better than writing 'and guest' and also 'and daughter.'