There are a few black and white ones that look like they could be SLW mixes, but it's hard to tell. I wouldn't keep them just because they're part SLW... it won't mean anything great. They might turn out to be excellent layers, and they might not. It's just a guess at this point. If you don't like their personality, don't keep them. There are a lot of great eggs available from other BYC members, and you might get exactly what you're looking for on here.
Can you send a message to the person you got the eggs from, and find out what they're mixed with?
Can you send a message to the person you got the eggs from, and find out what they're mixed with?