Generally, she has a hard time with characters that have safe to safe-ish zoning
IMO from worst to 'least' worst:
Quan Chi (Summoner)
Shinnok (Boneshaper)
Sub-Zero (Grandmaster)
Possibly:
Erron Black (Gunslinger)
Kano (Cybernetic)
IMO none are worse than 4-6 tho except maybe Quan. Although if she catches him she can 50/50 him for days, if she guesses wrong then she's either unsafe and gets vortex'd, or she forces herself to back off and waste precious meter(EX Flipkick), giving him a chance to zone again, so that's why Quan may be her only 3-7
For now tho I say none are worse than 4-6