Captain Cadaver said:
If they weren't #18's level in base, they'd have been eliminated fairly quickly, it's that simple. Before I hear the tired argument of "she was holding back", take into account that she did the same against Vegeta and quickly ended the fight when she became aware of his limit. There's no reason for her not to do the same against Mighty Mask after realising he wasn't a normal human. This is even backed up by the Daizenshuu stating Base Trunks fought evenly with #18.
It's pretty obvious that their SSJ selves were far above #18 regardless. #18 was fairly shocked at the power of a heavily suppressed Ki blast and even resorted to risking putting them in serious harm with the Kienzan to settle the fight quickly. That's far from the actions of someone on par with the kids.
It's best to assume that the suit acted as a major plot nerf, considering the kids were doing fine in base despite Trunks saying SSJ wouldn't make much difference in the costume, unless for some reason you believe the gap between their Base and SSJ forms is ridiculously small.
They don't need to be eliminated fairly quick in order for them to be #18's level in base. Lazuli, upon seeing Mighty Mask defeating a random earthling, only constated he's pretty strong for an earthling, and that his fists pack a powerful punch. THEN they charged at her, which wasn't enough of a demonstration for her to realize who she was dealing with. Throughout the fight, the kids were seeing struggling, sweatting, putting up effort whereas #18 remained nonchalant, with that boring face... she was still confused at the end of the fight, trying to figure out why they were moving in a so weird way. None of the sequence requires for her to be going all out against them.
Furthermore, when she notices who them in fact were, and noticing they transforming in a SSJ, she still remained calm and was happy to discover who they were, which obviously doesn't match a demeanor from someone who has been going all out and failing to COMPLETELY overwhelm their BASE form. If she were going all out, she sure as hell would be pretty worried at the prospect of engaging into a combat with someone who has experienced a huge power up through the SSJ, which was what Vegeta told her seven years ago.
#18 fights them, is still confused and trying to figure out what's going on. She THEN realizes who they are, sees their power multiplying many times over and STILL remains calm, ONLY changing her demeanor upon experiencing they are stronger than her (no, I never denied SSJ kids being above Lazuli)... so, obvious conclusion, she wasn't going all out and remained calm because she knew she wasn't putting anywhere near her full power. She could have ended the fight quickly, but she not doing so in thirty seconds doesn't mean at all that she couldn't. She was still testing them and could have decided to end it once and for all until seeing they are actually the kids.
They were in a restrictive costume, but still to think it'd prevent them from overwhelming someone whose power only amounts to 2% of their total power is folly, as, like already mentioned, Jackie Chun didn't even need nearly that gap on Yamcha to overwhelm him with a handwave from his hands. Heck, Goku DID the same against Chi-Chi, whose official battle power was 130, whereas Goku wasn't nearly 50x above her. Keep in mind Goku didn't even need to take out his weights to accomplish that.
Obvious conclusion: the kids are above 18, but not multifolds so, probably not even 2x as they had to still resort to a ki blast and didn't simply poke on her, or handwave her, or blew a current air on her, or finger flicked her.
Goten was giving Gohan problems, but considering characters have already displayed an aura and effort when not using full power (example: Cell), it stands a reason for Gohan to do the same fighting his little brother, where he could have been holding back to 16's level or so. It wasn't EXPLICITLY stated he held back, but still the logic applied in the #18's battle implies he did.
