Is it only my imagination, but do my party members MISS A RIDICULOUS AMOUNT OF TIME!?
There are a few things you should check/do:
1. Make sure Lae'zel is not wearing the
Gloves of Power - if you don't have the Mark of the Absolute you will be casting Bane (Negative 1d4 to hit) on yourself every time you attack. You get the Mark from Priestess Gut in the Shattered Sanctum. The Gloves drop early (at the Grove) and they are kind of a trap.
2. As mentioned before, Githyanki don't have Darkvision so you will want to make sure in dark areas you have a Light source. Torch, Sunwalker's Gift, Clerics Light spell (Shadowheart doesn't have this but you can get it for her at higher levels)
3. Use a potion of
Hill Giant Strength - they can be purchased from Auntie Ethel and sometimes other vendors. They last
Until Long Rest and set your Strength to 21, so you would gain + 2 to hit for Lae'zel.
4. You can also grab
Loviatar's Blessing from Adurak in the Shattered Sanctum - which gives you +2 to hit if you drop below 30% health (you can heal up after)
Hope that helps
