How do I explain to my 5 year old daughter when her friend (a boy) says he won't play with her because she's a girl?

So my daughter (just turned 5) was crying after school the other day because her friend who is a boy wouldn't play with her, saying it was because she was a girl. She said none of the boys would play with her after that. She was heartbroken, I really didn't know what to say to help her feel better or what advice to give her. She seemed to forget about it by the end of the day and yesterday she was back to playing with him, but if it happens again, does anyone have advice for me? She's my only child and I was homeschooled myself so school/friend issues are entirely new to me. Any advice would really be appreciated! via /r/Parenting http://ift.tt/2eGEBex