Jamie Lynn Spears traveled across the country to visit with her mom Lynne and sister Britney... and to show off her adorable newborn daughter Maddie!

Check out pix of grandma, mother and daughter in the HUGE gallery below...

But what about the babydaddy, Casey Aldridge?

Britney Spears seanjaydenbdayparty.jpg

Maddie's father was not present for Sean Preston and Jayden's birthday bash (pictured above) last weekend, either...

Hmm, is that just a coincidence or does Brit not want him around?