7 year Old Girl being Fresh

Ok Guys,
So I literally signed up just to bounce ideas off other parents....My 7 year old daughter is the youngest of my kids and is full of energy...loves dancing, playing her tablet, talking, etc....Again, she is full of energy, spunk, and sassiness...

But lately, she has become both: very affectionate towards me, but then very insulting. For instance, she loves cuddling and spending time with me and LOVES doing projects etc...but then in a blink of an eye can be very nasty, pouty, and 'mean.' We were playing uno with the rest of the family and BOOM-"I hope Mom loses....."

Last, I don't know if its just me, but she has become inappropriate. I notice things like if she eats something (banana, lollipop, popsicle-she puts her whole mouth on it) or she won't wear any clothes after getting out the shower and IM LIKE WHAT DO YOU THINK YOURE DOING? WE DONT ACT LIKE THAT.

Is this normal? I have 2 other children and this was never a thing. She is very observant, smart, and witty-so I feel like she knows that this is inappropriate but she does it anyway.....

HELP! We are at a stage where she doesn't get punished for this, but it has become noticeable to me.