Pop star Britney Spears has hand delivered a lawyer's letter to her estranged mother - but it's not a restraining order, according to U.S. reports. The troubled singer reportedly fell out with her mum Lynne earlier this year (07) for being 'pushed' into rehab after months of hard partying following her split from husband Kevin Federline. Spears was spotted visiting a Valencia, California movie set on Thursday (28Jun07) where her younger sister Jamie Lynn is currently working, and was seen handing over a document to her mother while exchanging a few brief words, before the 25-year-old stormed back to her parked Mercedes. Video footage of her impromptu visit has since surfaced on the internet. Media reports allege Spears was serving her mother with a restraining order, but TMZ.com claims it is actually a letter from an out-of-state lawyer. The site claims the Toxic hitmaker could not legally deliver such an order if she was the one seeking it. According to TMZ.com, the letter was a blunt request to Lynne to keep her distance from Britney's two young sons, 19-month-old Sean Preston and nine-month-old Jayden James, if she is on medication that could "impair her ability to be around them".