Naming Creatures

In my family, we have this habit of calling each other by names different from the ones initially assigned by our parents. My mother has several names for me. She calls me certain nicknames, pet names, but most of the times, they are really abstract descriptions. Like Punsch. Mind you, this is a drink (punch). But there's no further affiliation between me and this beverage. There's no funny backstory of a family celebration where I had too much of it and then danced around in my underwear or something. Nothing like that. I couldn't even tell you what it derives from, only, that these names seem to evolve over the years.

Some years ago she used to call me Pinscher, which is a certain type of dog. We never had any encounter with a pinscher. I distinctivly remember that Pinscher sort of melted into Punsch, but I don't know when and exactly why it happened. There's a phonetic similarity, yes, but that's about it.

Yesterday, as I re-wrote one of my short short stories, I thought about how difficult it is for me to give proper names to my characters. Most of the times, the ones I come up with for some reason don't sound authentic to me. Take Francis Miller as an example, I just don't believe anything that comes out of her mouth! And her husband Mark. And her sister Cindy. These are just awful names. They sound truly average and horribly stereotypical. But I don't want to re-name Mark Bronko just to give him an edge...

Of course, I wouldn't dare to pick fantasy names in a non-fantasy setting either. Artiall'gor is cleaning the dishes. No way.

And then I thought, how about doing it like my mom, taking a certain object and fabricate a name. Like windowsill. Mark calls his wife Windowsill. I could at some point give an explanation, why he calls her that, thereby revealing additional information on the character. I don't plan on doing this in general, but as a basic idea, what do you think? Writers, any objections?