Leaving a job...ethical question

[Tri-Tip]

Sorry for the long post, but background is necessary.

This for a friend of mine (really, it is), wanted TRF's opinions...

She has been with the same company for nearly 10 years. When she started, it was a family-owned, entrepreneurial company with many, many long time employees.

Four years ago, it was acquired by a "corporation" out of NYC and Europe. One year ago the prior owner stepped down from running the operation and a person from the Corporate Office was brought in as General Manager to run the company.

In the past year, 20 of the 25 department heads have had their "positions eliminated" or have resigned, as have many employees, some with 20-30 years of tenure. It's no longer a family atmosphere, and not an enjoyable place to work anymore.

My friend went out on Maternity leave in November, after the birth of her first child. Based on what is happing, she wants to find employment elsewhere. Someone from inside the company was trained for several months before my friend had her child, and has been doing the job for nearly 4 months.

Here's the question...If my friend wants to leave the company for a new job would it be wrong for her to just let them know that she will not be returning, or should she come back for a week and then give 2 weeks notice?

If she were not taking another job and choosing to be a stay-at-home mother, I don't think there would be any need to return, but that is not the case, she wants to work somewhere else instead.

Opinions are greatly appreciated.