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.