Jacqui is hella strong in this game, but I think this MU is a bit uphill for her atm. Mainly because a lot of the bs Cetrion does at range is harder for her to check, so she has to take more risks closing in. Take a character like Sonya who is also very strong with rushdown, but has the best projectile in the game (12F startup, virtually no recovery) and the MU is night and day from Cetrion's perspective.
I also play Jacqui but not on any level like I do Cetrion/Skarlet. There are universal issues in the MU, and Jacqui issues.
-At 3/4 away, a blocked boulder frame traps into Geyser. So if you block a boulder that pushes you back 3/4 away or farther, if I do Water Geyser and you do anything else other than block you'll get hit by it. So you have to anticipate if I'll do Geyser and block it, and then dash in or dash punch on reversal to close distance. Or you'll have to read that I do boulder and jump over it. That far away that's your only options. If you read wrong you'll be hit by one, or block another boulder pushing you even farther away to full screen.
-Jumping when at 3/4 to 1/2 away is dangerous because if I mistime boulder toss, it can still hit you on the way down. Also, this is the range where Fire Beam is most effective, and hits all jumps safely. It's the worst range to be at. Worse than even full screen imo because all her options are available at their peak. If you find yourself in this range play chess, and try to bet on safer risks unless really down on life lead.
-When you block a regular Fire Beam non-AMP, you should be able to reversal punish with Dash Punch. Then do another Dash Punch to close distance while I'm getting up.
-Same with Geyser, reversal punish unless too far to hit.
-When up close, her buttons are trash. F23 is -10 on block, so if I don't cancel into Wall, you can S1 punish to full combo. If I do AMP Wall, you can reversal punish Dash Punch. Or FLB full combo. Regular Wall you can full combo any time I do it, just be weary of the AMP. Reversal Dash Punch is the safest punish to trade off risk on Wall. F23 is a fraudulent stagger though. 21 is a good stagger but starts high, so if you predict it low poke or uppercut.
-The feints work wonders on her since she can't get out or away as easy as someone like Erron can. The reads are hard reads for her to not get over pressured by them.