DNA percentage

[PMY330]

I recently recieved a message saying I had a new relative on 23 & Me. It turned out to be a possible half sister with 33.4% match. My daughter shows up at 16.2% match but is listed as a 1st cousin instead of a half- neice. Is this an error or can the amount of DNA match be either?  

[EJ Blom]

You can fill in the numbers using this website: https://dnapainter.com/tools/sharedcmv4

and get an idea about the probabilities