Is my kid becoming a snot??

Yikes! Yesterday we spent the day at Nana and Papa's because my aunt and uncle were down for a quick visit. They haven't seen Bee for a few months so we were excited for them to get to see how much she has changed and how much she has learned! Plus, of course, to see how more and more beautiful she is getting! ;) When my aunt and uncle got the house she was sleeping so we all visited for a bit. After a while Nana said she thought she heard Bee and went to check on her. Daddy went in there as well. After a few minutes they emerged with what looked like my child but actions to come over the afternoon would prove that there was some sort of baby switch there for a few hours. She was immediately whiny and clingy to me. This may be caused by the fact that Nana couldn't help herself and got her up too soon. Sorry Nana, but true! I thought, okay, this is okay, give her some time and let her wake up, warm up to the new people in the room and everything will be okay. I'm okay, you're okay, she's okay, we'll all be okay! That did not happen! She refused to go to them. Some how my child forgot how to say please and thank you! Those are some of the first words she learned! She always says them automatically and with our prodding! Not this day though! I couldn't get her to say them, at all, to anyone! My aunt and uncle would talk with her and try to tickle her and she would ignore them or cry out if they touched or even went near her! It was awful! Then, it got a little worse. She finally warmed up to my uncle but for some reason not to my aunt. At dinner we put on some music and she started to dance. Which is so fun and she is too cute dancing. Well, every time my aunt tried to watch or clap along, like all the rest of us were doing, she would look at my aunt, point her little finger at her and say "No!" This killed me!! Any time my aunt tried to watch her dance she specifically told her "no!" So, we got through dinner and it was time for a bath. I got her in the tub and washed up and she was playing. My aunt came in to see her and Bee let her watch for a bit but then looked up and said "Bye, Bye" to her! My aunt asked Bee if she wanted her to go and Bee said.."Yes!" I was so sad! Why was my little, sweet girl acting like this to some one I adore and love!! All I can come up with still is that she was tired and well, she's turning two in a few months and they say the terribleness starts early! She finally started to warm up a little right before we were about to leave, of course! And snippets of the baby girl we all know started to shine through. I am still sad by the way Bee was acting and wonder, have we done something wrong? Do we give in to her too much? Am I a bad mommy and not teaching her well enough? I tried desperately to let her know her behavior was not acceptable but it seemed to go in one ear and come out the other! I read all about how the threes are worse and after this long day I am left wondering.... is the worst is yet to come? Don't answer that!