(Yahoo!) - Jamie Lynn Spears can cross another item off her bridal checklist because she's found her wedding dress!

And not just any dress; according to the "How Could I Want More" singer (and Britney's little sis), it's actually the "perfect dress," she wrote on Instagram.

For her shopping excursion at I Do Bridal Couture in Baton Rouge, Louisiana, the 22-year-old, who's engaged to businessman Jamie Watson, brought along her mother, Lynne, and 5-year-old daughter, Maddie.

"Thank y'all so much for making me feel so special and being so accommodating!!!!" she wrote.

As for dress deets, she didn't spill too much, but she made a selection from the Liancarlo dress line, according to the designer himself, Carlos Ramirez. His bridal gowns are known for feminine silhouettes, luxe fabrics, and handwork detail.

The "Zoey 101" alum, who is featured on Britney's new album and released her first single in November after taking time off to raise her daughter, announced her engagement in March 2013. She and Watson have been dating for four years, and he's a hands-on dad(-to-be) to her daughter with ex-fiancé Casey Aldridge.

No word on when Jamie Lynn will take the plunge, but it sounds like she'll be a stunner on the big day. And expect her doting big sis to be on-hand for bridesmaid duty.