so, is she equipping a Spirit to start the match with a rocket launcher?
i don't know how crest and spirit in that game worked, but i personally doubt she'll need one to use it since the humans in mgs are more or less like the normal humans in the three houses she'll have trouble using it but its meant that anyone can use it given enough time, snake's spirit would give it a jump start but what's really useful to her from snake's spirit is to able to do well in stealthy missions and espionage and also heal herself and grant buffs from just about anything she finds on the field