I hope you can help me!

My sister (really, my sister, not me) had a hysterectomy in November.  They were able to leave her ovaries in tact.  She is 43 years old and a mother of 3.  Over the past couple of months things have been going a little crazy in her life.  Out of the blue she told her husband that she was unhappy and wants a divorce.  She does not care about getting custody of her children - she just wants out.  This coming from a mother that consistently is hugging and kissing her children.  No one in our family saw this coming.  This is totally out of the blue.  My sister was always petite- about a size 4 but now her size 2's are falling off of her. 

All this started happening after her operation.  In your experience - could this extreme change of personality have to do with her going through menopause?

Dawn