Not a turd at all, pretty cool. Getting pummeled by Colossus and living is actually a great durability feat, she can help as a tank for the team.
I do have some advice for her strength which depends on your intentions. If you want strength to be her main asset then you may want to make her stronger like possibly 30 tons or a little higher and make it 70 tons. She wouldn't be at Colossus strength or broken in terms of strength, she'd still be very balanced.
If you want to rely more on her other abilities like the speed and fighting ability then at least 15-25 tons would be fine. Not judging you or your character, just giving a warning that by the two strength feats you've given then she's about like 1-3 tons. We'll be fighting some people that are way more durable than concrete. Being able to punch through steel isn't overpowered either as long as it isn't Vibranium or Adamantium.