I used to babysit for a lady and her 3 children, but I have not spoken to her, or her children, in over 2 years. She came up to me yesterday and said she was upset she wasn't invited to the wedding, and she should have been invited. She was really frustrated, but proceeded to say, "I got you a gift even though you did not include me and my family." I am going to write a thank you card for the gift, but do I also say sorry I didn't invite them? Or just leave it at thank you?