I personally wouldn't recommend allowing your chinesey to have a play date with your friend's hamsters. Chinese hamsters are solitary by nature and really should never be introduced to one another except for the purposes of breeding (which should be left to those who are experienced). Besides the inherent dangers of breeding, you could also end up with them having a fight. They may appear to get along, but being forced with other hamsters can be highly stressful and stress can lead to illness
Things can change in an instant and while they may get along just fine one day, they could kill one another the next and that's not a risk that I personally would ever take. Another issue is that disease could be passed on from one hamster to another and you could wind up with a very high vet bill, or worse even, a dead hamster. Your hamsters really wouldn't benefit from a play date at all, so instead perhaps you could just play with one another's hamsters individually? In the end it's your hamster and your choice, but please remember that it's only humane to do what's in her best interest
Glad to hear though that she's enjoying the new bedding!
I would love to see the picture of little Coffee with the Easter bunny