I always go to my friends parties but she never comes to mine.?

I invited my friend and her family to my sons birthday party in August. She said she would come but cancelled at the last minute. I invited her to my adults only birthday party in September. She said she hoped she could come but did not show up. She invited my family over for Thanksgiving, we went and brought desserts. She invited my family over for New Years, we went and brought appetizers and gifts for all. Then in January, I invited her for my daughters birthday party and she promised they would come. Then she cancelled two days before the party. What is she doing this? Should I stop going to her events since she's not going to come to mine?