Leggy Pauline is an Lady who is Laddy the Lucky Elf's girlfriend.
Pauline appeared in the Laddy shorts starting with The Banker's Daughter. However, the names for Laddy's love interests were never widely publicized, which is likely the reason she was given a new name in Epic Jariel, following the alliteration pattern of Jariel, Homer, & Marge's mirrored relationship. As can be seen in her character design, she was very much a precursor to Marge Simpson. Often in the original Laddy shorts, Laddy would compete with Mr. Burns for her affection.
As a side note, Pauline is an Italian name that means "gardener", something that some of her art related to Epic Mickey shows to be a hobby of hers.