Tunnel of Secrets

Chapter 2

Inside the house is cold. I mean I love being in the cold but this was unbearable.
"Dang it's cold in here!!" I said while looking around. Thankfully the movers had already put in all of the furniture.
"I know kiddo. Just let me find the thermostat and we'll have this house up and running!"
I went up to the second floor and quickly found my room. The walls were decorated with trees so it looked like a forest. There was a huge window that over looked a garden that had lavish flowers, an huge, ancient willow tree, and a gorgeous fountain that small birds bathed in. As I inspected the room closet, I noticed a price of paper sticking out from the dresser.
"That's odd," I mumbled to myself as I picked it up.
( looking at letter)
Dear Mama,
We finally found it!! The tunnels Papa told us about. We didn't get very far because Lilly said she was getting creeped out after we found that old book. I wish you were here. Sometimes I hear Papa cry at night because he misses you. But, I think you know that already. I know you had to leave because you didn't want the others finding us. I just miss you a lot.
  
                          Love,
                          Cathrin
( away from letter)
What did she mean by others!?
I didn't know there were tunnels around here. I rushed down stairs only to find father in the kitchen talking to some lady I've never seen before. She was wearing what looked to be gardeners clothes with her long brown hair in Dutch braids.
"Ellie, this is Cathrin. She's the gardener for this place," father said with a soft smile. Her name reminded me of the one I saw in the letter.
"Hello Ellie! It's a pleasure to finally meet you!" She exclaimed while giving me one of the friendliest grins I've ever seen.
"You too! Dad can I go out side and explore?"
" Um, sure. Just don't get lost out there!"
(Short time skip)
As I walked outside into the warm abyss also know as summer, I could help but think about who the little girl was and where were those tunnels.
Who was Cathrin and her family?

Was Cathrin in the letter and Cathrin the gardener the same person?

Why did her mom leave her?

Where are the tunnels?

I decided to answer them one at a time.
My mind also wandered over to my own mother. She never really did say why she was leaving us. Just one day she got up and said that she wanted a divorce and that was that. The only thing that her and I had in similar was our eyes. One blue and one gold. While I had red hair she had black, I had tan skin while hers was fair, and lastly I was tall while she was short. But I guess none of that matters now.