When should i be concerned about my daughter "sharing" her toys?

Mandy

Okay, so, my daughter is about to be 6 months old and her cousin is 8 months old. They've been "playing" on the weekends, which pretty much just consists of sitting near each other playing with toys. Well, her cousin is crawling and all over the place whereas my daughter is still getting the hang of just sitting up. I noticed that while my daughter was playing with her own favorite toy, her cousin became interested, crawled over and ripped it out of her hands. I'm not sure if my daughter was startled or actually upset about her toy, but she did start to cry a bit. My sister in law took the toy and gave it back to my daughter and told her own daughter "that's not yours! That's not nice."

I personally don't care. I mean, her daughter is only 8 months old and obviously she's still learning how to play. Same with my daughter. But I also don't want my daughter to think she will always get her way when it comes to playing, if that makes sense. When does "sharing toys" become a bigger deal? Is 6 months still a little too young? I wasn't offended by the situation or anything, but this has happened a couple times and I just sit there because I don't know how to handle it at such young ages. I just want to be a good mommy.