Heimish Mom, your remarks, though well-intentioned I am sure, sound a little petty. What do YOU care if someone wants to mark the simcha of having a female child (and it is a PHENOMENAL simcha), by making a Friday night get-together? There is no halacha against this, because it was never an inyan of halacha. It is no more assur or “am haaratzus” than is making a birthday party for a 12 year old girl and calling it her Bas-Mitzvah celebration, though I am sure you have something to say on THAT subject, as well.
IF something assur is being done at this party, then it is a whole different ballgame. Assur is assur. But please allow those parents who may possibly never have a male child (or even if they do, they are overjoyed to have a healthy female child), the same simple joy of inviting people to their home to sit down, eat nosh, wish them mazel tov, etc. that the ones making a Sholom Zochor do.
So what if they will make a kiddush? It probably will not take place for a while, unlike the Sholom Zochor which is within a few days. And though they will eventually make a kiddush, the boy gets a S”Z AND a bris seudah. Let them enjoy their little baby girl however they want. It really doesn’t hurt you any. To call it something of the Reconstructionists and Reform, sounds not only judgmental but shows a lack of empathy for another person’s expression of simcha. I know plenty of very frum people who have made and attended these types of celebrations. If you do not want to do it or go to it, then by all means don’t. But please do not disparage people who do. They are doing absolutely nothing halachically, ethically, morally, socially or legally wrong. The worst thing I can say about it is it’s fattening. (And I take that under advisement ’cause I don’t believe you gain weight when you eat on Shabbos).