I don't think anyone can tell you that, tbh. DH would have been contagious even before any symptoms appeared so you both might have caught it already. Also, DS could have had it first- some cases of SF are apparently very mild.
Well depending on how much contact your dd has had with your dh, it could be that you can reduce her risk catching it through profylactic use of tamiflu (10 days half dose). When dh was suspected to have swine flu whilst on holiday in Summer 09, we had all been close but the moment it was suspected he stayed in one room and we in other room (holiday appartment) and dd and I went out as much as possible (was Summer), both dd and I were given tamiflu profylactically and we did not get swine flu. DH was given the full dose of tamiflu (for five days) and it was later confirmed that he indeed had had swine flu. So it did work for us, but clearly our situation was different as dd stayed with me. If your DH has swine flu I suppose he might feel too ill to look after dd. Also, the more contact between your dd and dh the greater the chance she will pick it up (but she might be lucky and not pick it up at all of course). The advantage of your dh already being on tamiflu is that it reduces the shedding of the virus. Would it be possible for your dd to stay with somebody else? Also, what would you want to do if she does get it (i.e. if you want to stay with her, it may be a better bet to see if you can postpone your holiday). Good luck and I hope you can sort something out.
just happened to look up some stats on this! They did a study which said that the risk of catching it was about one in eight for household contacts, though about twice that for children. I'm sure you can influence the risk with avoidance strategies though!