Given the difficulties in explaining the character suddenly being able to use magic, I think I'm going to just play Maria as a regular fighter.  Given that, what's the best way to give her a ranged capability?  Should I give her a javelin?  Or maybe put some of the points I was going to put in INT into DEX and have her carry a short bow?  It is possible to transition between weapons in a timely fashion in 5e?  (Maria's primary weapons are probably going to be a sword and shield.)