Vayikra 12 says that after giving birth a woman is tamei for 7 days for a son (12:2) and 14 days for a daughter (12:5). I am aware of the g'mara on Niddah 31b that says that everybody rejoices for a male (so she regrets her negative reaction to the pain of childbirth sooner) but for a girl people are disappointed so it takes her longer. I find the g'mara's explanation unsatisfying for two reasons:
It's not like we don't need daughters too; aside from other considerations, a man needs both a son and a daughter to fulfill p'ru ur'vu. Wouldn't they celebrate the daughter that allowed him to fulfill that obligation?
This doesn't match what I've observed of new parents. Admittedly there are probably different attitudes in the 20th and 21st centuries than there were at the time of the mishna, but the women I know who've given birth are deeply affected by having given birth and whether it's a son or a daughter doesn't seem to enter into it. Was it really so different then?
Are there other interpretations of this difference that I might find easier to relate to?