The Story of a Divorce - S1-E14
Revealing mistake: In the scene where Reba and Parker kiss outside the restaurant, you can see creases in the scenery backdrop behind Reba.
Up a Treehouse with a Paddle - S1-E21
Revealing mistake: When Brock finds Reba holding baby Henry in the kitchen, you can see a doll's face in the blanket.
Answer: I believe it was "Seeing Red" from season 2.
Karoo