Good old Value Village - there, I found a long white nightgown, a white tablecloth, and a white turtleneck to make up most of the dress portion. I got a string of tiny LEDs with an attached battery pack from Dollarama, and made the flame out of coloured plastic bags. At Michael's craft store, I got black rubber coated wire, which I am going to cover in thorns made of electrician's tape. My friend is giving me a heart shaped Christmas ornament, which I just have to paint red and decorate a bit. I will likely affix this with velcro strips to the dress portion.
Gold ribbon will probably be purchased to trim the tablecloth veil, and hair clips will be purchased to make sure the veil affixes properly to my hair. The crown should be simple and fun to make - light gold card stock should do the trick, or card shock I could paint gold later on, if I can't find the gold kind. Then it's just a matter of decorating it with any interesting bling I come across.
I need to borrow the Anglican Druid's pearl style rosary to carry - the shoes will be white flats with flowers attached to them. The fact that the Sacred Heart glows will really make the costume, I think - I tried the LEDs in the dark in my bathroom and it looked marvelous.
I think I'll do pale makeup with rose lips, maybe gold tears around the eyes, though I am not sure about that just yet. I will update again when I get somewhere with this costume to show photos.
Also - might sing the following at Hallowe'en karaoke:
"Maria" - Blondie