ABANDONED. Children's book series dwarfs balloon adventure

[Reavers]

Kids books like fern hollow but with dwarfs one was a balloon adventure

[MB (What she read)]

The Borrowers Aloft? (A long shot because the Borrowers are not dwarves.)

[Jill]

The Littles were small creatures like the borrowers but they have tails. Here's one in the series but not sure if it involves a balloon:
https://www.goodreads.com/book/show/1...

[Cheryl]

apparently abandoned