Whatever sho will do she can’t win against that much of high tier servant, Jalter alone can take care of her
Even she look like that Jalter is very strong servant ,Basicly normal jeanne with huge upgrade,buffed stat ,Unlimited flame np and her defense np now has reflect function ,in exchange of losing cheat tier MagicResistance EX
However, this is an art error, those spikes were apart of her arm wear, since she wore bridal gauntlets, not actually in her palms.
Actually, from what official art I could find, and especially screenshots from the Fate/Apocrypha anime, the spikes appear to indeed project directly from her palms... even though her FGO ascension artwork and sprites seems to like any such spikes.