lindiaan, I think in most countries it is up to you where you want to be buried and you should write your wishes down. However, there may be some other things to take into account.
If we are talking burial here, not cremation, as I assume, it does depend on the size of the burial plot the family bought when the widow's first husband died. You can only be buried in a plot, if there is room for a second coffin - this applies to a plot you bought and to a pre-existing family plot, and must apply to a mausoleum too.
Anyone who has been married twice should take into account if there are children of both marriages, that choosing to be buried with one of the husbands is potentially hurtful to the children of the other. I think, I would opt to be buried on my own, if that were the case.
If a cemetery has been closed for any reason then you probably cannot be buried there, even if all your ancestors are.
Jewish and Muslim cemeteries usually only have numbered plots, even although Jews do put headstones with the departed's name on, so you are buried in the next available plot even if you have a former husband somewhere else in the cemetery, unless it has the kind of arrangement which some Jewish communities have of reserving a space for the widow or widower beside the spouse who died first.
