It's fine. Just be sure not to let the wire that attaches to the coin touch the water
RE: How about if I make the cathode to anode ratio 1:2 as suggested by some people.
The ideal is to keep a larger anode than your cathode. Therefore, using the coin would be fine as it has far more surface area than your 14ga wire.
Hope this helps
PS. don't forget to add some form of current control, if not, be sure to pull the process before things get to far, as this will result in the formation of crystals, which looks like a stream of blue or white smoke coming from the anode.