Is my friend self centered ?

Recently my friend invited many of us over for her son's 2nd birthday party. When it was time for the cake she lit the candles and blew them out herself without giving her son a chance to do so. Her husband even asked why she didn't give her son a chance. It was a bit awkward but we moved on. When ever we are out in a group it seems like the moment I try to talk to anyone else she tries to get my attention by interupting. Why does she do these things ? At times I am embarrassed for her.