It is nice to see how many kids these days speak Welsh. :)
Liwsi / Lwsi is the Welsh spelling of
Lucy, and sounds pretty much exactly the same.
Nel is usually short for
Elen /
Elin, but I've been seeing it as a full first name quite a bit lately.
Grug is Welsh for heather; u is a short i sound in Welsh, so somewhere between 'grig' and 'greeg' with a rolled r.