In the hands of you two hits vs non-burning candles. Show them to the audience. Then momentarily connect them together wicks, say "spell". Above them appears the smoke and after - fire. Dilute candles in different directions - to the amazement of the spectators, they spontaneously ignited.
How to achieve this? Two of these (same size) candles prepared in advance. The end of the wick of one of them sprinkled with powder of potassium permanganate, and the other impregnated with liquid glycerin (enough for 2 or 3 drops). Use glycerin and potassium permanganate cautiously. If such wicks connect to withstand a short pause until reaction occurs, both candles will be burning.
Just keep candles away from your face, clothes and other flammable items.
And remember that all tricks with fire require special care and skills, they can do only with adults.