Officially as a therianthrope Vesper must abide by some house rules for going monster mode. This includes changes to trigger a change which gets worse over time if this condition isn't cured.
To make a Player Character have werewolf stats as needed we shall be trying a modified version of the rules found in Tasha's Guide To Everything, in the Barbarian section, page 24, for “Form Of The Beast”. This seems like a decent experiment for balance. Should this character reach level 6 & this experiment has panned out well we will consider the similar “Bestial Soul” rules.
Summarized:
House Rules
To add in house rules, a werewolf PC may not illogical skills while in werewolf mode. An athletics check is logical. An attempt to pick locks or something is not. Hit points remain unchanged. Can't speak while in form. Etc, etc.
To humor werewolf lore in this game we're going to say they are particularly vulnerable/sensitive to silver & perhaps we will find out what happens if/when silver comes into play. They do not however have pact tactics because as a player character they are not used to having a pack, so that makes zero sense for now.
In most attempts at rules for werewolves the options for a player character's belongings become to have them transform with the werewolf. This happens in a lot of movies as well. We're going to use that for simplicity for now. One moment person with gear, the next a werewolf, because simplicity in game is good sometimes. Should the werewolf revert or die, all the stuff reappears. As a fun aside however if magical items are on the werewolf at the time of transformation, the werewolf will radiate magic at an equal level as those items would should anyone be able to track that sort of thing.