I think it's a lovely idea. My 7 yr. old just went to her first "tea party" and loved it. You know your guest. Some men enjoy tea. Offer alt. as suggested above. Ask the people if they still have a treasured teddy bear from their childhood. (I have one and my dad kept his.) They could bring it along and your could have a little table set up for the teddy bear tea party, plus the adults could maybe share a bear memory w/ your daughter for some bonding time. I just joined this group, so hope I'm not too late in the reply. Have fun!
IT doesn't have to be. A friend did a tea party themed wedding shower for my daughter. They served finger sandwiches, finger desserts and had each table decorated with different tea pots, very nice. Each table had their choice of type of tea. IF you have just women, you can add hats and gloves. IF men are invited, they need to learn there is more to life then football, just kidding. It's your daughters party and it sound lovely.