You could not have a non-dwarf Corgi. Yours looks like a Corgi to me. At 6 months she may be leggier than when she is mature.
Some claim to have a corgi and they're not-volunteering at the shelter, we get lots (even from other shelters) of "corgis" Just look for corgi on Petfinder-a while back-like 1000 corgis-maybe<20 and maybe 5-6 that looked purebred. Some on CL even go to the trouble of making bogus papers on Googleform....
None the less, she is adorable :) That intent stare at you in the middle pic--too cute!
Corgis ONLY carry the gene for dwarfism so a pure Corgi can't be non-dwarf. But the gene is dominant to some degree and so even half-Corgis usually have pretty short legs. Wait to see what she looks like when her chest fills in; she might not be as leggy as she seems now. She's cute, regardless.
She could have another breed or just poor breeding. She is adorable and looks like she is well trained since she's waiting so patiently for her treat in her bowl. Enjoy her!!!!