so or and?

[嘟嘟嘟嘟]

As Mom spoke, the postman came up to the house, and Liz's dog, GG ran to the door. She barked and growled angrily. "GG, be quiet!" scolded Liz. She turned to her mother. "Mom, what is wrong with GG? She should know the mailman."
"Because she has just had her babies, she wants to be sure they're safe, ______she doesn't quite trust anyone she doesn't know really well." Mom paused,...

For the blank, is "so" or "and" right? I think it is "and", but the answer is "so". Thanks for help!

 

[MikeNewYork]

Both words work for me.

 

[tedmc]

1. She wants to make sure the babies are safe, so she doesn't trust people she does not know well.
2. She wants to make sure the babies are safe, and she doesn't trust people she does not know well.

If you use "so", the 2nd part follows from the lst.
If you use "and", the 2nd part is independent of the lst.

Both can be used, but the lst is preferred.

not a teacher

 

[MikeNewYork]

Preferred by whom?

 

[tedmc]

Preferred by whom?

By logic.

 

[bhaisahab]

By logic.

Not at all.

 

[Matthew Wai]

Perhaps it is tedmc's own logic.

Not a teacher.

 

[bhaisahab]

Possibly, Matthew, possibly.

 

[Tdol]

Both forms work for me too.