Generally, female sterilization means cutting or removing the fallopian tubes. The eggs and womb (uterus) are still present and functioning, but the pathway for the eggs to travel is no longer available. In other words, eggs wouldn’t need to be frozen in case a future pregnancy was wanted. However the eggs would need to be removed and mixed with semen, like in vitro fertilization, for a pregnancy to actually occur.

So, it’s a fun reference to her previous work.

So then not a joke, but a reference. I understood the reference but failed to see the joke. Maybe I am just overly pedantic.