Jessie,
I'm glad you reached out to this forum. There have been some young donors on this site but for obvious reasons most people with very young children like yourself don't volunteer to donate. I remember one young donor was donating to her spouse and of course there are others who donate to their own child. I hope some of the young moms could help out on this one.
I am also a mom, of 4 daughters and donated when they were 19, 18, 14 and 11. I think the feeling that you have, "the what ifs" never goes away no matter how old your children are. I did worry that if something happened to me my children would be left with just my husband to raise them. It is a scary thought. I prepared my will, health care power of attorney, wrote a pre surgery letter to my husband and thankfully with grace of God, none of those documents needed to be put into place. But anytime you have surgery, and even more so an elective surgery, we do think about the risk. It is an anxious time.
Because you have young children who need your physical attention, lifting, bathing, changing etc you will need to make sure that you have enough help around the house when you return home. There is no lifting more than 10 lbs after surgery for at least 6 - 8 weeks (like a c section or hysterectomy). Listen to those guidelines so you do not end up needed more surgery to correct a hernia. So make sure you do not play the martyr and say you don't need anything because you will. If possible, the recipient or other family members may be able to help defray the cost of some extra cleaning or babysitting help. If possible talk this out as a family so that everyone will be in safe and healthy place.
How does your partner/spouse feel about the donation? Do you have a support system from parents? This also plays a factor. Use the services at the hospital or through your own insurance if you need to have a few meetings with the social worker to discuss this prior to surgery. I know you mentioned you feel like you can't back out now, but you actually could. Yes, there would be difficult emotional feelings but if you are not 100% sure you are ready to do this now you can speak with your nurse coordinator and just say you need to decline at this time. The match to donate needs to be compatible on a medical and psychological level. They will let the family know that something came up during the testing that makes you ineligible to donate at this time. You could also postpone the surgery if you feel the time is not right. I'm not sure of your 16 month old niece's health history but if she is on peritoneal dialysis she may be able to stay on that a little longer until you know for sure you want to do this now or until another donor is found. You are less than a year from giving birth yourself and have a full plate so it may be a vulnerable time for you to make a truly informed decision.
How did you feel about meeting with the transplant team? Were the doctors, nurses and psychologist on board with you donating being that you are a young mom with an infant and a toddler? Did they have concerns? Reach out for help from your team. That is their job. Some are better supporters than others.
I hope that you are able to come to peace with whatever decision you make. What helped me was having a supportive husband and friends and knowing that I was in good professional hands. Being on the other side is much better. I am sorry that you have been put in this position. It isn't easy but please know you have the love and support here on this forum whichever way you choose. Please keep us posted. Would love to know how things work out for you and your family.
All the best,
Sherri