It is simply not true that all abortions at this stage are necessarily painful and definitely not worse than childbirth at full term.
Yes, because most abortions at this stage are terminations for medical reasons, they tend to be highly traumatic for the mother. But that doesn't mean they have to be painful.
Depending on the mother's health and the actual developmental size of the baby, a number of different procedures are available.
I am fully aware from talking to women who have had this done to them, that some American abortion clinics use unnecessarily painful procedures. They often don't even know that other options are available. But we can manage pain extremely well for all manner of medical conditions and surgeries and injuries. In order to speed recovery and enable the patient to go home faster, it is very common to reduce pain relief fairly quickly where this doesn't slow down recovery. The opposite is also possible where this is better for the patient. It is therefore highly likely that this woman will made as comfortable as possible while she is in the hospital.
And I can understand why her mother was fighting to continue the pregnancy. This may well have been her only chance to have a grandchild. I think it's quite likely that I would have fought tooth and nail to secure that precious grandchild. That doesn't mean she doesn't love her daughter. It's just possible she wasn't in a good position to objectively weigh up what was in her daughter's best interests.
I feel desperately sad for all of them.