Triplets mom advice please

We just found out that our twins are actually triplets. While we knew this was a huge possibility since we saw a third sac we didn’t think it was going to happen. We also are being told something baby be wrong with baby C. It is much smaller. We are planning on revealing it’s twins at our gender reveal in April to our family. Is it wrong that we are planning on keeping baby C a secret between just us till birth ? We don’t know what’s gonna happen and we want to just enjoy the pregnancy. We plan on surprising them when they are born. Also how many of you have had a 3rd baby with problems? Did it survive ? Thanks in advance