Hard to tell! I honestly think it's so much easier to sex them at 2 days old than at this age ;D Do you have other babies you definitely know the sex of you could compare to? Please don't take this as fact because I could be 100% wrong, but left maybe looks like girl, and right maybe looks like boy? Hard to see.. At about 4-5 weeks a boy's testicles usually drop (but not always!) and it's more obvious. If you're still not sure about gender, just be sure to separate them at 4-5 weeks old so they can't breed. Do you know how old they are now?
Just be super cautious since they're maybe a mixed sex pair. The boy's testicles might not drop "on time", so if you're still unsure by the time they're 4 1/2-5weeks old, keep them seperated until it becomes more obvious, and for sure post more pictures here when they're maybe a week older and it might be easier to tell.