It's not a huge party- it's just about 12 of us getting together. I don't want to have a huge gift, I was just thinking something small and pink or blue. She isn't holding this to get gifts, but I'd hate to be the only one showing up without one. I was planning a 10 dollar gift for each gender...
This exactly one of the reasons why I hate these parties. People who throw them insist 'Oh, it's not for presents, it's just to celebrate the baby, blah blah blah" and you are validating that guests feel obligated (if not by the host, by the social pressure to not be the only guest without one) to go out and buy presents.
Honest question time: If your friend was NOT having a gender reveal party, would you feel obligated to (or just plain old want to) carry around two presents (one of each gender) for the moment she told you what she was having? Probably not.
When someone throws a party, be it birthday, housewarming, bbq, baby shower, wedding reception, retirement, what-so-ever, people feel obligated to bring something. Sometimes it's a present, sometimes a bottle of wine, sometimes flowers, but regardless, people who have been raised properly know and feel that it's rude to go to someone's house for an invited event and not come with SOMETHING to give the hostess/guest of honor.