Brian Laundrie's sister shared texts and postcards she said were from Gabby Petito, not long after a body was found in the search

• Brian Laundrie's sister shared postcards she said Gabby Petito sent her from the couple's road trip.
• Cassie Laundrie sent condolences to Petito's family after a body matching Petito's description was found.
• The full results of the autopsy are expected on Tuesday.

The sister of Gabby Petito's boyfriend shared on Monday postcards and texts she said the 22-year-old sent her from the couple's road trip.

Laundrie's sister Cassie also offered her condolences to Petito's family in a statement on Monday that said, "Gabby was a fun and loving influence to 'the boys' as she always referred to them," ABC News reported.

A body matching Petito's description was found on Sunday near Grand Teton National Park, Wyoming, after a massive missing-person search. The results of an autopsy are expected on Tuesday.

Throughout the search, Brian Laundrie refused to assist authorities and went missing himself last week.

"The boys" in question are Cassie Laundrie's children, to whom she said Petito addressed cheerful postcards from her road trip with Laundrie.

Signing the cards "Aunt Gabby," Petito appears to have written about the things she had seen in her "van-life" trip.

"Oh my gosh! Me and Uncle Brian were sitting on a rock eating a snack after a long walk, and the fattest squirrel I've ever seen!!! Came right on my lap!!" one card said.

"The sky here is so open, there's more stars than I've ever seen!!" said another card, apparently from Utah's Bryce Canyon National Park.

Other cards shared with ABC4 showed colorful drawings of rock formations. "The rocks here are so cool!!" one said.

"Uncle Brian and I have seen many different rock-types, I knew there were different kinds of rocks, but I didn't know that some are different formations, did you?" the card continued.

The text message, dated August 10, was similarly upbeat. It mentioned the children's return to school and requested pictures of them.

"We're in arches right now so we don't have be best WiFi, but we did send you some mail," the text said. It also included a hugging emoji. Arches is likely a reference to Utah's Arches National Park, which the couple's social media suggested they visited.

Cassie Laundrie is the only member of Laundrie's family to have spoken directly with media since Petito went missing. She gave ABC News an interview on September 17, in which she described Petito as being "like a sister."

Two people believed to be law enforcement were seen visiting Cassie Laundrie's Lakewood Ranch home on Monday, Fox 13 News reported.