Is my girl in heat?

I have a 6 month old Labrador girl who is exhibiting some signs of heat but I’m not sure. She’s normally super sweet and playful but lately she’s been getting aggressive with us. She does not have a history of being aggressive. We also noticed that she won’t stop whining. She’s always been vocal but never to this degree. My husband even commented yesterday that she’s been whining almost constantly. Recently she’s also been going to the bathroom every 15-30 minutes when previously it was every hour or two. Finally today out of nowhere I can’t get her to play because she’s been licking her lady spot almost nonstop.

This is my first puppy and so I’m unsure and especially concerned because I’m going out of town and to help my husband who’s a tax accountant a friend of mine is watching her. I just want to make sure I’m not about to dump a dog in the middle of heat on my friend.

Lastly, pics for fun!