Mila isn't that unsafe as far as I know. And she can easily go into her sidestep grab. Leifang is linear, and her mid circulars are all mid string, so she's really vulnerable to that setup from Mila. You then have the choice to break it and be at a disadvantage, or simply take the damage. Not too great. Mila also outspaces Leifang because she has faster ranged moves and can move around faster than her.
Tina is a bad matchup due to her grabs mostly. They are so powerful, so it's better for Leifang to leave her parrying at home. Tina is also a good crusher and has nice mixups. She has a superior ground and wall game to Leifang too. The only stage where that doesn't affect the match much is the Tatami stage (the empty one), and maybe Dead or Alive since it's quite big.
People say JL is linear, but he really isn't that linear compared to Leifang. He has quite a few circular moves. He has a low, a bunch of mid ones, and a few high ones, and he doesn't need strings to actually use them, but they are individual moves. All of Leifang's circulars that are not highs, are from strings, so she can get hit out of her strings before the circular hits the crushing move of the opponent. JL also has superior sidestepping moves. His sidestep P currently leaves him at +0, which basically means he still outspeeds you, even if you block it.