It’s hard to discipline when they’re so little and cute, but it’s really worth it. Be consistent (and make sure everyone else is too), if you say it-mean it, and don’t forget to praise good behavior, even if it’s just lying calmly by your feet. And before you know it she’ll know right from wrong and you can just relax and enjoy being with her.
My lab mix is two now and he’s a (almost) perfect gentleman, a joy to be around, and loved by all. So, so worth it!
(PS, if you haven’t done this before, I highly recommend picking up a training book—very helpful.)