For the moms I would do a nice hand cream or even a single fresh flower in a bud vase (tulip, calla lilly - something springy), which could also be part of your tablescape until the end of the party. Then let the moms take the flower home.
For the daughters, you could give little girl make-up or jewelry. Anything they could play dress-up with, but yet is still small.
Since it is a tea party, you could also ask everyone to wear hats and gloves and floral dresses, etc. That may be going to far with it, but some may want to participate.
If you can't find devonshire cream, use a nice quality whipped butter and strawberry jam with your scones. Scones are very easy to make.
If you google "tea party ideas" or "tea party recipes" you will get lots of sites to check out.
Here are a couple to get you started:
http://www.seedsofknowledge.com/teaideas.html
http://www.chiff.com/entertain/tea.htm
http://www.sippingtea.com/ideas.html
Also, some nice Victorian or nice classical music in the background might be nice during your party.
I don't know what scale of party you are doing. But I used my best white linen tablecloth and napkins to match, tiered trays, silver trays, crystal, etc. for the food presentation. I also had two different sets of blue and white china that I used together that coordinated beautifully but were not the same pattern. One was a floral, the other a toile/transfer ware pattern.
Have fun with it! You can go all out, or you can go smaller budget.