Must ghusl be re-performed and prayers be made up after sticky, non-bloody brown discharge appears following ghusl from menstruation and prayer, or is what was done considered correct?

This brownish discharge that appeared after purification is not menstruation, and your prayers are valid. You are not required to perform ghusl, based on the saying of Umm Atiyyah: "We did not consider the brownish or yellowish discharge after purification to be anything." A woman recognizes purification by the white discharge (al-qassah al-bayda') or by complete dryness. Brownish or yellowish discharge, if it occurs continuously with menstruation, is considered part of it. However, if it appears after purification has been confirmed, it is not to be given any consideration.