Hi C.,
First I'm gonna so no and go have a good time. Are you being selfish (no) and if you were than so would I.
3 years ago my husband and I went to St. Louis for the weekend with no kids and it wasn't for business. Did I feel guilty for leavin' them a little. But at the sametime my husband and I enjoyed every single last minute of it. We have 4 children and at the time we only had 3, for us going to Mc Donald's and spending $8 for the 2 of us to eat breakfast/lunch was awesome and we so badly want to do it again.
On another note did I miss my kids YES very much so but I knew they were in good hands (they stayed with grandma and grandpa) they even enjoyed it more than we did, they got to eat ice cream for breakfast (mommy and daddy don't do that), and stay up past their bedtime. I will say again go, run as fast as you can, have a good time. The time that you will be away from your daughter will be good for everyone, You and your husband get to spend quality time together, whoever she is staying with gets to have some quality time with her, you get to have lots of ME time and with it being a business trip I would imagine there will be times that your husband will have to do something so you will have to find something to do like go to a spa, go shopping, etc.
Have a good time, bring back your daughter a few presents and make good use of your hotel room.
W. mom of 4.