Accidentally skipping mom boss fight

So my girlfriend has been playing isaac for the about 2 weeks trying to beat mom for the first time. Recently she was on a really good run that was on track to beating mom for the first time until she decided to take a pill that gave her telepills and teleport her to a I am error room. This was super cool to watch happen but she ended up skipping the mom fight completely and going straight to mom's heart and beating it. So now right now me and her are wondering, is there any way to get the epilogue ending now if she skipped mom? What about the mom specific unlocks and achievements? I've never seen this happen and we're both curious. She's currently playing afterbirth if yall are wondering version.