Paper Plate Seder?
My cousin recently relocated to the East Coast and will be joining my family for the Passover seder this year. She keeps strict kosher, however, and we do not. We obviously won't have any bread at the seder, but we don't own separate Passover dishes or buy kosher meat. Should I offer to buy separate pre-made meals from a kosher caterer or grocery store, served on paper plates, or should I leave it to her to make her own arrangements? I already have plenty of work to do in preparing for the seder, but I also want her to feel comfortable celebrating with us.
Paper Plate Seder?
I am curious as to how your cousin came to be on the guest list. Surely someone involved in coordinating the attendees of this family seder knew of the differing dietary habits between you and your cousin and may have thought, more than a few days before, that this should be addressed. Regardless, here you are, and you're right to be concerned that this will be extra work for you! A few honest conversations and straightforward questions should minimize the impact, though.
You need to speak to your cousin directly and find out exactly what her requirements are. You also need to find out what, if anything, she is expecting or willing to do in order to feel comfortable eating at your home. Her responses could range anywhere from "making compromises so that the family can be together" to "bringing all my own food and dishes." However, having you make an entirely separate meal with less than a week's notice is not an acceptable expectation.
Ask direct and respectful questions, and feel free to ask follow-up questions related to the specifics of what you already have planned. For example, "Would you eat charoset made in my kitchen if all the ingredients are certified kosher for Passover?" and, "If I buy pre-made food from a kosher caterer, would it bother you to have it heated up in my oven?"
After the initial conversation, give yourself time to think everything over and schedule a follow up call. At that point you can say, "Based on everything you've told me and everything else I have to do, here's what I feel like I can do to accommodate your needs." Give her a list. Everything that you can't do, she'll need to do herself or perhaps enlist the help of another family member more familiar with the local shopping options.
If you'd prefer to minimize the differences (and save yourself a lot of effort), you could consider serving everyone on paper plates. Yes, it's wasteful, but Passover is a lot of work, and my feeling is that you have to make decisions that help make the holiday feel like a celebration and not a chore.
Then, the night of the seder, welcome her and everyone else to your table with open arms. If anyone points out or questions the different food options, say that even though there are varying observance levels within your family, you're so glad that everyone can come together at one celebration.