This is a eeeeeeewwwwwwww gross situation more than a risk for anything. I'm sure after you realized that it wasn't a rubber glove you had them wash their hands anyways. The skin on the hands is too thick normally for std's , including herpes, to penetrate and infect. The odds that active virus was 1 - on the condom are incredibly low in general and 2 - still alive at that point even if there was virus once on it because it doesn't thrive well away from body temperature is also incredibly low odds. This wasn't a risk - just an oh ick situation that one day you will all probably get a good giggle out of :)
genital herpes is transmitted thru direct skin on skin contact with the genital area of the preson infected. This is not a risk to anyone who is not having sex with your stepdaughter's bf. You all can do laundry together and use the same shower and soap etc. The virus is easily killed with soap and water too.
grace
there is not a definity how herpes is spread some websites say it can be spread by shering same utensilis some say only by sex the best thing is to be more clean hope this helps.