Rare Meet-Up of Janet & La Toya Jackson for Janet's 60th Birthday, See Pics

La Toya Jackson was showing Janet some sisterly love for her upcoming 60th birthday ... sharing some shots from a sweet celebration on Instagram.

On Thursday, La Toya posted a montage of photos and video from the outdoor bash ... including a rare pic of her with her sister.

Janet -- whose birthday isn't actually until the 16th -- kept it pretty casual in baggy jeans and a white T-shirt that says "Rock and Roll" ... but was snapped sporting a "Sixtylicious" sash for her big day.

La Toya was a bit more dressed up ... in a wide-brimmed hat and a statement collar and cuffs. She captioned the post ... "Jan’s 60th! Love seeing family, friends and just relaxing!"

She recently squashed speculation that Janet and Jermaine Jackson were beefing over the 'Michael' movie, telling Entertainment Tonight at the premiere ... "There was absolutely no problem whatsoever. None whatsoever. And please believe it."

No sign of Jermaine in La Toya's post ... but it still looked like everyone was having a good time.