Setbacks?

Well I was just bragging about how well Kassi was doing with her potty training and then yesterday, two accidents with Grandma and one with Daddy. Grandma says she still won't tell her when she needs to go...ever. Wes was asking her last night and she said no I don't need to. Yet she used it for me three or four times between coming home from work and bed time. Kassi is a very intelligent little girl and I often find myself speaking to her more like she is 12 than 2. So I sat down with her and asked her how come this was happening. She was doing excellent for me, but not having as much luck with Grandma and Daddy...I wish I had not asked this question...the response. "Because I miss you mommy and your not home during the day and I just want you home."
Okay she is almost three and already knows how to play on moms emotions! What am I to do...as much as I wish I could quitting my job just is not an option. I guess the potty training battle will just have to continue.