what you are missing is you're conflating very different things and asking a question in order to elicit a response that isn't relevant to the situation.
abortions performed at the 22 week are nearly all done for medical reasons. if this baby were born without a brain stem, or born with a 3 chambered heart, or were somehow in the condition of Teri Schivo, or had terminal cancer, then it would be totally within the rights of the next of kin to pull the plug. having an abortion at 22 weeks is only comparable to these things, and this is why abortion remains legal up until the moment of birth. please, do some reading up on abortions that happen after the first trimester and you'll see that it's not comparable to a mother killing this particular baby and more comparable to someone pulling the plug on terminally ill patient. and those 2nd trimester abortions that aren't for medical necessity are usually had by very, very young teenagers who haven't grasped the idea that they are pregnant.
if this particular mother didn't want a baby, if the pregnancy was accidental, and if she had an abortion, it would have probably happened long, long, long before the 22nd week.
since the mother wants the baby, and the baby was born healthy (relatively), there is no reason on earth to end the pregnancy since, guess what, it is no longer a pregnancy.
let me ask you this: would you rather a mother have a first trimester abortion, or, give birth to the baby and then leave it to freeze to death in a dumpster?