I am fairly certain that elvish laws and customs would not permit divorce but if we let that slide .... yes it is a common tale ..... boy meets girl and after a few millenia when the kids have gone they realise they have nothing in common anymore and want to do their own thing ......
Only trouble would be ... who deserted whom? By her departure Galadriel might have been interpreted as leaving him not only the marital home but the marital kingdom which would be a more than generous settlement - even if she did keep the jewellery..... I mean it is not Gally's fault that he chooses to over extend his resources by taking on a second new realm and ends up ligging off his grandsons at Rivendell.
Furthermore an adulterous relationship with a dwarf would surely (to elvish minds) denote clinical insanity and I am not sure if you are allowed to divorce a lunatic .... (NB The Downer Legal Beagles should not interpret this as instruction and attempt to charge me for their opinions.....
) but admittedly there is an outside chance that the legal system my have moved on since the days of Charlotte Bronte ...........