❤.M.
If you want it to be nice, I would do it a "Barefoot Contessa" way.
She will take white table cloths, nice silverware, a few clear, tall vases filled with freesia or small vases w/white tulips.
White plates.
White cloth napkins make things have a nicer feel.
Don't use cheese decorations like streamers.
You coul hang a few (5) colorful balls. They have these that look like
pom-poms so they aren't cheesy looking.
String up white lights around the backyard for a bistro vibe.
I wouldn't do any games or activities. You could have a fancy notebook
that guests could take a page out of, write down a funny thing about the
guest or a wish for her 30th year then have them drop into a fancy silver
bowl.
I wouldn't do any activities. I would just have music playing, candles in
lanterns (so they can't get tipped over).
A toast to the brithday girl.
Maybe some old pictures of her up if she won't get upset.
Edit: I would add those little light stakes around your backyard for cute ambience. You can get them at the Dollar Store.