Put myself in a tough situation

The story:My brother and SIL are planning to get married in October. They struggle with money, and they live halfway across the country away from all of our family and friends. SIL has a rocky relationship with her parents. Originally, they were going to pay for her wedding, but changed their minds.In order to help them out, my husband and I offered to host their wedding in our backyard. Just a casual party that they happened to be getting married at. We are very excited! In addition to hosting the wedding, we also told them we would pay for their officiant. They loved the women who married us, and we told them that if they wanted her to marry them, we would pay for it.Well, our situation has changed a little bit. We ended up getting pregnant sooner than expected (literally the day i got my IUD out) and now our baby is due 5 weeks before the wedding. My husband also tore his rotator cuff and has missed a lot of work because of it. He's in a trade, so he has to be in good physical condition in order to work.Okay, no big deal. The wedding will go on as planned, I will just have a few less hands to help out and I probably won't be able to enjoy as many adult beverages as I had planned!I think hosting the wedding will be pretty stressful with a newborn, but we have a lot of support and I think it will be okay. The problem, though, is that now I'm worried we will be putting ourselves in a tough spot financially paying for the officiant. The women we used is $400, which wouldn't have been a problem before I knew I would be going unpaid for 6 weeks. I don't want to back out of a promise I already made, but I am also worried that we are being too generous with our gift at the expense of our family. I know that we should never have committed to that kind of gift so early, but I got over-excited for my brother and wanted to do all that I could. $400 wouldn't have been a huge deal to us if I hadn't have needed to take unpaid leave and my husband's health wasn't uncertain.With that, I was hoping to hear some suggestions from you all. Would you try and book a cheaper officiant? Would you try and see if another family member wanted to go halfs on the gift? I know they are already going through enough stress with planning the wedding so the last thing I want to do is put this back on them. Is my only solution to just go through with the gift with a smile on my face? via /r/weddingplanning http://ift.tt/2vd1OtD