Nothing can come between a sister's love — not even an overseas adoption.

Aubrey and Avery Lumpkins were living at the same Chinese orphanage until Aubrey was adopted by an American family when she was 9. When Aubrey flew to her new home in Kentucky, she left Avery behind — without ever knowing they were actually sisters.

Read: Family Discovers Adopted Daughter's Long Lost Twin At Chinese Orphanage And Now Wants To Adopt Her Too

But last year, her adopted mom, Lisa Lumpkins, was scrolling through Facebook and noticed a young girl that looked remarkably like her daughter. She contacted the orphanage and DNA tests found the girls were indeed related.

Last week, Avery flew to America to reunite with her sister. The Lumpkins family, who gathered at the airport to welcome her, adopted her, too.

The girls, both 13, have picked up right where they left off, their mom said.

"They're loving being together," Lumpkins told InsideEdition.com. "They remembered being [at the orphanage in China] together, but they had no clue they were sisters."

She said that while Avery has been bonding with everyone else in the family, including four other adopted children and two biological children, it's obvious she and Aubrey have a special relationship.

"She's so protective," Lumpkins said about Avery, whom she suspects is Aubrey's twin.

Both girls have cerebral palsy, but Lumpkins said Aubrey has more trouble walking.

"Aubrey likes being really independent," she said. But when Aubrey approached a set of steps, Lumpkins said she watched Avery instinctively stick her arm out, and offer her support. "She knows Aubrey won't ask for help, but she was afraid Aubrey was going to fall."

Likewise, Aubrey has become extremely attached to her sister, even though Aubrey doesn't speak Chinese, and Avery has not yet learned English.

The long-lost sisters were only able to be reunited last year, when Lumpkins saw a picture of a girl on Facebook that looked nearly identical to Aubrey, whom she adopted in 2013.

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"I was speechless. I was like, ‘Wow! She looks just like my daughter,'" Lumpkins told InsideEdition.com in a previous interview.

She eventually asked the adoption agency to run a DNA test, which confirmed the two girls are related. Lumpkins decided she would have to bring the sister home.

After a battle against time (a Chinese adoption law required children to be adopted before age 14 or face eviction from the orphanage) and a scramble to raise enough money through their GoFundMe, Aubrey's biological sister, Avery, became the latest addition to the Lumpkins clan.

Read: Mom Who Wrote a Letter to Adopted Daughter 20 Year Ago Gives it to Her on Her Wedding Day

As Avery met her new family at the airport last week, Lumpkins said "Avery's hollering Aubrey's Chinese name, 'Ha Mei.' All the way down the escalator, she was crouching down, yelling her name."

Leading the way was another girl they decided to adopt at the last minute, Molly: "Her face lit up like a Christmas tree. She was like 'Mom, mom!' She hollered as loud as she could."

"I think that made everybody cry," Lumpkins said.

Watch: Couple Drives 32 Hours to Adopt Blind Dog as 'Brother' to Blind Dog They Already Own

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