Thank you for your reply :)
The problem can be several things but I do think this will work itself out, especially since she is not showing any aggressive behaviors towards the pup.
If you can take them to a friend's house, even, to get out of the home turf for some play time that would be wonderful. Doggy daycares (which my apologies as I meant to say day care and not dog park) will allow you to use the facilities to do this also. :)
Your girl may have a bit of a bent nose...puppies need lots of attention and she may be feeling sore towards him because he is getting your attention and she isn't. Make sure you give her some space away from him completely for some playtime with just her alone. When playing with the pup, encourage her to join in...a new toy may entice her.
Bring them for walks together. Make sure they both stay behind or next to you...never out in front of you. This establishes the pack order. You the alpha and they are part of your pack. :)
This normally works itself out after a week or so...especially since she is definitely young enough and not a senior dog with a new pup.
Just make sure you don't condone the behavior by saying things like "its ok baby, mommy/daddy still loves you" She will get confused and think its ok to behave the way she is. Just let her go be by herself when she needs to....even the best dog needs a break from a young active pup.
Good luck and let me know if you have any other questions regarding this...I'm happy to help. :)