SOLVED. Cousins Time Travel Through a Mirror with a Monkey [s]

[Teresa]

I read a book in elementary school (mid 1980's) about a pair of cousins who time travel through a mirror with their pet monkey. All the while, there is a villain after them...if I recall correctly, the villain was trying to get a necklace that the female cousin wore.

Thanks in advance for your help!

[Tab]

Teresa, was this part of a series?
What time period did they time-travel to?
Anything about the cover?

Any other fantasy elements, like witches, dragons, trolls, etc?

[Heather]

The Ear, the Eye, and the Arm?

[Teresa]

That's not it, Heather, but thanks anyway.

Tab, this was a stand alone book. The cover showed the cousins standing on a stage in front of an ornate mirror. One of them may have been going through the mirror and the monkey was pictured, as well. I believe this may have been a Scholastic/Troll/Arrow book.

Oh and the cousins travelled to different times, all in the past, I think. They went to the 1800's, they went to 1976 during the bicentennial celebration, they witnessed Isaac newton's apple incident, etc.

There were no other fantasy elements, that I recall.

Thanks so much for your help!

[Diana]

On the Far Side of the Mirror has a cover exactly as you described:

[Teresa]

Yes, that's it! Thank you so much, Diana!

[Diana]

My pleasure!