Use shockwave granade

Luckily I had a quick save i could use but i only have like 3 grenades

If you have really nothing left and can't even heal up Jefuty, then yeah you should restart the mission and be conservative with medkits and bombs.

Lige will always go for Jefuty if she's within her attack range, put her on the flowers and block any adjacent empty tiles with barricades or your other two characters (she'll try to avoid the flower tiles if possible), when she uses her dash attack, put any two deployables (Turrets, barricades, scanner, decoy) in her path to stop her from obliterating whoever is targeted.

i made some barricades so her only route was in the flowers and got her in 3 turns but I did have to restart the mission and I leveled the characters up a few times they were pretty underleveled

Restarting a mission is really sucn an awful feeling but you are forced to restart a mission only in 1% of cases. You must have a save where you are preparing for Lige boss. Its possible to kill her even without Mendo ult with turrets (Ive messed up and lost all his SP but still did it by just normal attacks and some low-cost skills)

yeah I had no sp fighting her just blocked her with barbed wire and then fire grenade then moved and revived whoever she killed