Is AUTHOR wrong in the post ? POST : My husband is in the process of enlisting in the air force and money is tight for us, but we wanted to get married before he shipped off in a few months time. 

Originally I had not planned on having a reception party or even buying a wedding dress as we are trying to save money for our future. 

After telling my sister about our plans (a courthouse ceremony and a small reception dinner at a local restaurant) she insisted she wanted to make the day special and that she had bought some decorations for the reception dinner. She also offered to pay for half the cost of a dress that we picked out together.

In total she spent about 350 dollars on the dress/supplies. I was grateful for her help and especially for the dress. It was beautiful!

3 weeks later and the wedding was wonderful! I thanked my sister for making our day special even though we were trying to be frugal.

Well fast forward a month and a half later, and now my sister is saying she's short on her bills this month and is asking us to pay her back not only the money she paid for the dress (that I wouldn't have gotten if she hadn't offered to pay for half of) and the supplies she bought without asking me. 

My husband is annoyed and thinks she's only asking because she knows we've been saving money. We can afford to pay her back, but we dont want to because we're trying to save for a down payment on a house for the future. She told us before she spent the money that it was a gift. 

I'm not sure what to do. Im a little hurt that she's now asking for her money back, but I love my sister and dont want her to struggle to pay her bills or damage our relationship.

WIBTA if I refused to pay her back the 350 dollars when she needs it for bills?

tl;dr: sister gifted us 350 dollars to help with wedding expenses then a month and a half after the wedding is asking for it back to pay her bills.