These are very loose estimates...
Usually we can accommodate up to 4 guests having their nails done at a time, but I've only seen three. That would depend on the of nail technicians scheduled for the time you plan your services.
Usually there are two estheticians scheduled at a time to provide facials.
Usually there are 4 to 7 massage therapists scheduled who can do massage, scrubs, body treatments, and hydrotherapy.
A Nine year old can have nail or facials, but an adult would need to accompany her if it was a massage or body treatment.
So.... all four in your party can definately be accommodated and have your treatments at the same time

And plan some time after to lounge in the whirlpool and or steam and sauna after!
As far as recommending services, there's something about EVERYTHING we offer that I love! For what I personnally do, The hydrotherapy treatment is phenomenal. I think I see the most relaxation from guests with that one. It's definately a treatment that will melt you! The Algae wrap is another that I love getting myself. It does amazing things for your skin as well as your body. The parrafin wrap is warm and enveloping. The maple sugar body polish smells great and softens and hydrates your skin.... I could go on and on

I guess I'm a little biassed
Hope this helps a little!
Aimee K