Complex sentence: Marsh added that it was alaways planned for Ciaran and Michelle to begin a relationship after Duffy returned and said she and Duffy wanted the audience to feel that Michelle and Ciaran had "earned this romance" so it was a "slow-burn".
Split into simpler sentences: Marsh added that it was alaways planned for Ciaran and Michelle to begin a relationship upon Duffy's return. Marsh said that she and Duffy wanted the audience to feel that Michelle and Ciaran had "earned this romance" so it was a "slow-burn".