So, what happens if you never got a chance to request the heirloom you wanted before your relative died? If a will exists that clearly spells out exactly which objects go to whom, then unless you want to spend time in probate court, it's best to abide by the wishes expressed therein.
But if the relative didn't leave a will or was vague about the distribution of his or her estate, how do you go about making your wishes clear? In general, it's best to get everything out in the open as quickly and clearly as possible. To do this, try to arrange a meeting of all possible legatees. In this forum, everybody can express their wishes and the matter can be fully discussed. If such a meeting can't be arranged, try circulating an open letter in which you explain how you feel about the object in question and solicit the opinions of the rest of your family.
Whatever mode you choose, make sure to communicate as clearly and as openly as possible with everybody concerned. This should help avoid those dreaded family squabbles in which people pick sides and hold grudges for decades.