Is it permissible for the bride to pray in her wedding dress and makeup, while covering herself with an abaya and head covering, or should she combine the prayers?

Mere wedding celebrations are not an excuse to delay or advance a prayer from its prescribed time. The bride must perform each prayer at its designated time, wearing modest clothes that cover her 'awrah. If she encounters significant hardship, she may combine Dhuhr and 'Asr, and Maghrib and 'Isha, either by advancing or delaying them, due to necessity and hardship, as permitted by the Hanbalis. This is based on the hadith (definition) of Ibn 'Abbas, which states that the Prophet (peace be upon him) combined two prayers in Medina so as not to cause hardship to his Ummah.