Free Step Dodge

Because you can't mash buttons with her in close like Christie, GenFu or Helena.

You can't really button mash against her either, with all her crushes and deep stuns. World of hurt for mashers. Either way, I'm really enjoying her atm! =D

She's nowhere near top.

she is very strong o_o

And Gen Fu is basically broken. "Strong" doesn't mean shit to the real top tiers.

Bass is very strong too .

What? so to be top you need to be broken? I'd hardly call Lei-Fang or Kasumi broken and they're up top. I don't see how she isn't. The only thing she lacks is ninja speed, but other than that it's fair game =\

There's no such thing as "ninja speed." The only ninja that can match speed with characters like Christie and Pai is Kasumi. Hayabusa is slow as fuck, for example.
And Leifang and Kasumi are not top tier. And even if they were, Lisa still would not be top tier because she is not half as good as Leifang.

As far as what she "lacks," she has the slowest mid speed in the game (save the upcoming Nyotengu), she has a measly stun game, her heaviest unbreakable throw is the weakest of any grappler-based character, she has no parries and or expert holds and her environment damage is okay at best.
What she DOES have is a good spacing/zoning game. But that's not magically putting her in top tier.

^ Brute's pretty much got it.

Lisa does great at long range, but as soon as she gets in close range, and isn't at advantage, she can struggle. Her neutral speed is awful in close, and she has one of the worst stun games in 5U. Her crushes are great at mid range, but in close they're nothing special compared to say... Helena. Lisa effectively lives or dies off of her spacing.

Is there a way I can see the Lisa's you're VSing? =S her stun game is fine, the ones I've come across are great. Her NH stun game isn't great- but she isn't the only one that suffers in that dept. She has BT cancels, and plenty high crushes. A CH throw ( the one where she slides around them. ) does pretty hefty damage. She's got great OHs. Like you're saying, good spacing/zoning.

I'm not saying she's Gen Fu level, but she can very well hold her own against Lei & Kasumi. Kasumi's slightly more of a struggle, due to her speed but all her crushes render Kasumi's 9f punch pointless. People should be scared to attack Lisa, with her OHs, crushes and her billion options.

from PP alone you can pretty much do anything! PPK = guard break into dash. PPP tracks, PP4 leaves her in a solid BT state in which you can do BT 4P which will crush highs so people can't beat her out of it. ( it is throw punishable but that's just one of the plenty options she has -_- )