Ashlee Simpson to Sis Jessica: You Make Me a "Better Person"

Ashlee Simpson-Wentz is supporting her newly single sister Jessica on Twitter.

"Everyday you move me to be a better person. I love you..miss u so much," Ashlee wrote Tuesday to Jessica, who has been in Japan filming her new VH1 series, The Price of Beauty. "You are a perfect friend and sis. Thank you."

See how Jess and Ashlee's love lives compare.

Tony Romo dumped Jessica on the eve of her 29th birthday in July, causing her to cancel a Barbie and Ken-themed party. (Still, mom Tina said last week the family "still likes" him.)

Look back at Jess and Tony's grossest PDA moments.

"Les Miserables 'On My Own' -- can't sing this song without u ever. But it's my fav!" added Ashlee. The Broadway tune includes lyrics: "Pretending he's beside me / All alone, I walk with him till morning."

See who else is single this summer.

Jessica appreciates that her sis has her back. "I could never imagine getting thru the day without the love we share. I feel so far away!! Just wanna have pillow talk," she posted on Twitter in response.