Name help: My sister had a girl, thought she was having a boy...?

My sister had her baby last night, and we were all anxiously waiting the arrival of a little boy, but it turns out the doctor got it wrong and it is a little girl! Anyway, no matter what had happened, we are still overjoyed, but the problem is, my sister and her hubby picked out a boys name, and didn't have a girls at hand. The name they had picked out was SIMON TAYLOR, and luckily the middle name is unisex (they don't want Taylor as the first name though), but they weren't sure what to do about Simon. I suggested that they name her Simone, but my brother in law hates that name for personal reasons, so my brother suggeted Symon, which is apparently a more feminine version, and my sister thought that might be okay. So, do you think Symon Taylor would work for a little girl, or should they not use the name Symon at all? Do you know of any names that are close to Symon/Simon? Thanks :)