(music-news.com) - Britney Spears has sent Christina Aguilera a gift to congratulate her on the birth of her first child. The 'Gimme More' singer - who has lost custody of her own sons Sean Preston, two, and 16-month-old Jayden James - has sent a collection of baby clothes to her former pop rival for her two-week-old son Max. A source at children's clothing company huddybuddy.com revealed: "Britney ordered the entire collection of onesies to be sent to Christina. The slogans on the suits she ordered include 'Diaper Dude', 'I don't play well with others', 'I didn't nap today' and 'I know I'm gorgeous'." Britney, 26, lost her supervised visitation rights to Sean and Jayden after she refused to return them to ex-husband Kevin Federline on January 3. Following a three-hour stand off with police she was hospitalised for a psychiatric evaluation. The 'Piece of Me' singer is believed to be bipolar and reportedly has multiple personality disorder. Her lawyers are said to be negotiating the reinstatement of her visitation rights to her sons if she agrees to psychiatric treatment. Britney visited the Santa Monica office of psychiatrist Deborah Nadel for an hour on Friday (25.01.08) as part of the agreement.