Your first obligation is to your immediate family (husband and child). However, all family is important. I think it's great that your trying to save for a house, however, spending some money to travel for this unique circumstance isn't going to break the bank.
Since you mention your husband's paycheck, I'm guessing your not working. Therefore, why couldn't you drive, take a train, or a bus? Or why can't your daughter stay home? This would make the trip affordable for you.
You said your not very close to your father, but what about your brothers and sisters? This would give you an opportunity to visit with them. Would any of them be willing to help you with the cost?
Maybe you could give your father a call and explain that you would really like to be there, but unfortunately you can't afford it at this time. If he really wants you there, maybe he'll offer to help pay part of the cost.
Last year our family (hubby, myself and 2 girls) traveled over 5,500 miles to go to my father-in-laws birthday. We didn't have the money to go and had to dip into our savings, but knowing how happy it made him and seeing the look on his face when he grandchildren arrived made it all worth it. And yes, when he found out we were coming he did offer some money to help pay for the expenses.