Britney's father Jamie – currently her sole legal guardian – has asked a Los Angeles Superior Court judge to add his future son-in-law as a co-conservator.
According to People, this means he will have a say in her general well-being, including areas such as food, clothing and medical care.
What it doesn't include, however, is control over the 30-year-old's finances.
LA lawyer Jeffrey S. Cohen – who is not involved in the case - tells the US publication:"This is a very unusual situation, because generally you don't see conservatees get married.
"This could be a sign that the couple's wedding is around the corner."
He adds: "This is probably a compromise between Britney, her father and Trawick to get the marriage off on the right foot.
"Obviously, her future husband needs to have a say in her well being."
Britney's dad took legal control of his daughter and her assets in 2008 after she suffered a psychological breakdown.
The conservatorship will only be lifted when a judge is convinced Britney is well enough to manage her own affairs.