The best directions I have to find Tabetha:

Follow the road out of Theramore[it's the safest way] all the way around till it starts heading south. You'll go a good ways south, too. When you come to a crumbled stone tower on your left hand side, go just past it and head east into the swamp. Look for the large island that has a bay, it looks kind of like a reverse C. Tabetha's semi is at the northern curve of that island, and theres a dock out front with an orchard next door.

inside the building: 46, 57

This quest leads to 2 quests:

[Hidden Secrets] (https://vanillawowdb.com/?quest=1949 https://vanillawowdb.com/?quest=1949)
- Speak to Magus Tirth (https://vanillawowdb.com/?npc=6548 https://vanillawowdb.com/?npc=6548) in The Shimmering Flats
- He will give you the quest Get the Scoop (https://vanillawowdb.com/?quest=1950 https://vanillawowdb.com/?quest=1950) walk to ""Plucky"" Johnson (https://vanillawowdb.com/?npc=6626 https://vanillawowdb.com/?npc=6626) and type /beckon and he will change to human form. Talk to him and you get the password.
- Get back to Magus and get the next quest Rituals of Power (https://vanillawowdb.com/?quest=1951 https://vanillawowdb.com/?quest=1951) you have to get the book from Scarlet Monastry Library it's found at the start of the last corridor in a bookcase.

[Items of Power] (https://vanillawowdb.com/?quest=1948 https://vanillawowdb.com/?quest=1948)
- Get the Bolt Charged Bramble from gathering 10 Witherbark Totem Sticks (https://vanillawowdb.com/?item=7273 https://vanillawowdb.com/?item=7273) then bring it to Circle of Outer Binding. Use the Witherbark Totem Sticks in the middle of Circle of Outer Binding and get it from it. Return to Tabetha.

After you've done these 2 quests you get the last quest which contains the rewards: Mage's Wand (https://vanillawowdb.com/?quest=1952 https://vanillawowdb.com/?quest=1952)