The 'Beautiful' singer, who has buried the hatchet with Britney, called the hip Los Angeles baby boutique Petit Tresor, to order presents for Sean Preston and Jayden James.
According to US People magazine Christina told co-owner Nina Takesh: "I want to give them something adorable for the colder weather."
The 'Dirrty' singer - who is currently touring Europe - chose two blue cashmere schoolboy sweaters for $129 each.
Britney also called Takesh for advice on what to get the boys for Christmas.
The 'Toxic' singer asked for, "something matching and playful" and chose two Kaloo chairs, shaped like teddy bears, for $85 each.
Last week Britney apologised to her fans for her flashing misdemeanours and wild partying since filing for divorce from Kevin Federline.
The 25-year-old mother-of-two admitted she may have gone too far after being photographed without underwear on four occasions.
In a statement on her official website, Britney said: "I probably did take my new found freedom a little too far.
"I look forward to a new year, new music and a new me."