When I first met her in The Battle of Orleans (English Side), I was only level 32 and she charged me from no where, with  20 fully upgraded Royal Lancers that were Level 64!

She killed me in one charge, however, I was able to stand up to her and defeat her with Camels, but that took mostly the whole day (10 minutes) to do. If it wasn't for John Talbot, I don't think I'd ever be able to win the battle as Leon usually got killed by the other French Officers and John Fastolf wasn't doing much except getting killled while he tried to retreat, and respawning at Tourelles (the base you have to defend for 3 days) to repeat the process.

Talbot was very helpful in repelling La Hire and Gille de Rains, but he was no match for Joan of Arc.