Miss Manners: Am I overthinking which card to use for this thank-you-note?

AdviceYou can send your questions to Miss Manners through her email, dearmissmanners@gmail.com.Dear Miss Manners: I occasionally receive little packets of homemade cards that have been created by artistic, talented friends and neighbors. These may have photos or artwork covers, are blank on the inside for writing personal notes, and often have a small graphic or notation on the back, such as, “Created by ...”I am pleased to receive these unique notecards as they are different from store-bought cards. They are tastefully done and very pretty. But is it good manners to use one of those cards to write a note to the person who created it?I would like to return one with a handwritten message thanking them for their kind gift. That way, they know I was pleased by the gift and that I am actively using the cards. They would now also have a copy of the card as a testament that their gift was appreciated.On the other hand, might they construe it as an affronted commentary? I don’t wish to imply, “There! That’s what I think of your homemade gift — you can have it back!”I truly would not want to offend them, as I really do appreciate their gifts and have already made a point of thanking them.Gentle Reader: It is more gracious, Miss Manners thinks, to use one of the cards given to you — not only to show that you know what to do with it (judging from the general lack of thank-you letter writing, not everyone does), but also that you are enjoying it.It would take a true insult collector to think that this was your way of returning the gift.Dear Miss Manners: I am having the family Thanksgiving dinner for my sons, my sisters and their adult kids. My niece sent me the following email:“I’ll be there!! And if it’s OK, I would like to bring my roommate, Sasha. She won’t be able to make it back to her home for Thanksgiving.”I am not fond of this niece, and thought it was very nervy of her! I responded: “Glad you can make it. I am waiting to find out how many are coming. Being in a townhouse, space is tight and I am trying to figure out seating for dinner. Will get back to you.”She sent my response to my sister right away, adding the word “Really?!?”My sister, who is very controlling, sent me a message soon after: “If you feel that your townhouse won’t accommodate all who would like to come, I will have Thanksgiving at my house. Please advise.”Please tell me how to respond. I am fed up with their behavior!Gentle Reader: Your dislike of your relatives notwithstanding, your niece did not just show up with someone extra. She asked nicely — and it is Thanksgiving.In the spirit of the holiday, and family harmony, perhaps you could find space for one more person. Miss Manners thinks it worth it to protect your own reputation from being considered controlling.Please send your questions to Miss Manners at her website, www.missmanners.com; to her email, gentlereader@missmanners.com; or through postal mail to Miss Manners, Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106.Judith Martin, who goes by the pen name of Miss Manners, is an author and columnist on etiquette authority. Martin graduated from Wellesley College with a degree in English. She began her career in writing as a...