I find it utterly trendy and rather odd-looking (and I don't know whether it's 'sheelin' or 'shaylin'). Also reminds me of 'shieling', which makes it a strange word name (though I suppose no different to
Meadow or
Leigh /
Lee).
As for the meaning of the name, I doubt it has one, it looks like a train crash between
Sheila (or
Sheelagh) and
Lyn.