In order to reunite Sparrowtail with her family, give her a Yellow tulip (this can also work with a pink tulip if you are a tom) then when she said " Fine! Ill take it, just do what I said! " go to Goldenstrike and talk to her. When she saids " I wish she knew... " go back to Sparrowtail and tell her what you just heard then go back to Goldenstrike, keep chatting with her and then after the conversation finishes, talk to Sunnygaze (the one near the Leader's den) or a brown cat. (Forgot the name but is one of Coldstone guards) and they will respond with " Yeah, I'd love to meet her! " then enter where Plumclaw does patrol, go to the left and click the downwards arrow. After you've done that, go to your right until you see Sparrowtail. Click on her and now you completed your quest!