The Dark Descent of Elizabeth Frankenstein question

As you may have guessed from the title, this thread will contain spoilers.

So, I read this book in audiobook form and have listened to the ending several times now trying to sort out what happened.

(view spoiler)[
On my first reading, I thought Adam and Marry just pulled Elizabeth out of the water, but as I reread it, I leaned more toward the interpretation that they had resurrected Elizabeth from the dead using Victor's method. This is supported by the sensations Elizabeth describes while unconscious/deceased.
(hide spoiler)]

So, what is everyone's thoughts on whether or not there is meant to be a definitive interpretation of the ending? Or, do we think the author left the ending intentionally open to interpretation?

Please share your thoughts here in this thread!