Yes, I’m familiar with that sort of construction. I’d say it places the focus more directly on her (“she”) – which is quite appropriate if “she” is the one who has to do the “getting over”:
She thought she would be a long time getting over this ==> She thought it would take her a long time to get over this.
She thought it would be a long time getting over this ==> She thought it would take a long time to get over this.
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