Jenni 'JWoww' Farley is ''freaking out'' about her pregnancy.

The former 'Jersey Shore' star is expecting a baby with her fiancé Roger Mathews, and her close friend and co-star Nicole 'Snooki' Polizzi says she's not too happy about gaining baby weight.

Snooki - who a 15-month-old son, Lorenzo - told E! News: ''She's definitely freaking out, she doesn't want to get fat.

''She's working out twice a day - she's insane. But I gave her a copy of my book ['Baby Bumps' - about how her pregnancy changed her], so my book's helping her. And any questions she has she knows she can come to me. I'm always here for her.''

While Snooki is looking forward to Lorenzo having someone to play with, she's not sure that if Jenni has a girl she'd let them date when they get older.

She added: ''I feel like they're going to be more like cousins, because Jenni and I are like sisters. I think it would be weird if they hooked up or started dating. I'd like to raise them like they're cousins.''

Snooki, 26, is also engaged - to Jionni LaValle - and thinks she'll be the first to walk down the aisle.

She added: ''It'll probably be me because she's pregnant. She was going to have a summer wedding, but now I think she's going to wait another year, so mine will come first.''