Any theories/ideas on where Mrs Teavee was taken by the Oompa Loompas after she fainted in Willy Wonka and the Chocolate Factory?

To the Taffy-Pulling Room.

Earlier in the movie, when Augustus Gloop is sucked up the tube, Wonka tells Mrs. Gloop that the pipe Augustus went up goes to the Fudge Room. He then summons an Oompa Loompa and says:

"Take Mrs. Gloop straight to the Fudge Room, but look sharp, the little boy's liable to get poured into the boiler."

Later, when Violet blows up like a blueberry, Wonka tells the Oompa Loompas to take her to the Juicing Room for squeezing. Mr Beauregard is led away too, immediately following his daughter, so it probably can be assumed that he is being taken to the Juicing Room too to stay with his daughter, like Mrs. Gloop was taken to be with her son.

Veruca Salt is immediately followed down the chute by her father, so Wonka does not actually send him anywhere, but based on where the first two parents were taken, it stands to reason that Mrs. Teevee was being taken with her child to the room in which his condition could be remedied. This location was the Taffy-Pulling Room:

"Fortunately small boys are extremely springy and elastic, so I think we'll put him in my special taffy-pulling machine. That should do the trick. To the Taffy-Pulling Room; you'll find the boy in his mother's purse..."

After she faints, two Oompa Loompas drag her away immediately after the Oompa Loompa with Mike in the purse.