Hi Moo,
Start training her now to sit/lie down when you meet up with people. She can learn to be calm and happy instead of out of control and happy :P Work on it beforehand of course... daily 2x for about 5 minutes since she's so young. It will only take a couple of days for her to learn how to sit and lie down.
To sit:
Use treats (wisely ;) ) to get her in the right position. It's probably easiest if you drop to one knee first to get you down closer to her 'living space' :). Think of her as a teeter-totter. Push down slightly on her backside while bringing her collar area back. Or use a treat in your hand to bring her head/shoulder back when you push down on her butt.
Tell her to stay (just a second) and as she holds it for that split moment- release her with a chosen word that you'll use throughout her training. (hint: don't use 'good girl') My two it's "OKAY" said in a certain way. Then praise her a moment ---
After she's mastered "Sit" for a couple of days -- move on to "Down".
That's very easy to do with a small dog. Tell her "Sit"...... then "Down" at the same time, take your left hand and push gently on the spot right between her shoulder blades. She'll probably resist, but keep pushing straight down. Trust me, she'll lie down in a moment... just don't let her backout/wiggle free of your hand :)
I've yet to meet a dog that doesn't give in after a couple of seconds and lies down without any fuss. Now, I just put my hand on Chienne or Samma's shoulders and they collapse in a heartbeat even when they're standing up :rolleyes:
Do the momentary "Stay" and release word ....then be happy :) :) :)
As she gets older, the "Stay" will get more ingrained and held longer. It will take time and patience, but that's part of having a developing puppy :) :) :) ;)
You can always work on sit, down, and stay in little moments during a day....food - outside requests -- YOUR dinner time ;) Then just make certain you have her in hand when other dogs appear and reinforce it with her then.
hth
good luck,
toodles