It depends whether your friends' kids are healthy or not. If they have a compromised immune system then maybe you shouldn't take your kids to see them for the time specified above.

But if they are healthy kids, then they can't catch the disease from the vaccination.
If it was dangerous to have a vaccinated kid near an unvaccinated kid then we would all know it, because younger siblings would be at risk every time their old siblings were vaccinated - clearly this isn't the case.

The live virus vaccines are an attenuated virus, not the "real thing". It provokes an immune response from our bodies that will (probably) protect us from the disease, but a healthy person can't catch the disease from the vaccine.