I think that I can answer this. I had same problem, and did this:
 

textSprite.drawToImage('myText.png');var sprite = new Sprite('myText.png');

That solves the problem for me  

Cool, thanks man. I didn't know you could do that.

But are you actually creating a PNG image doing that? Where is it saved? Is there a more lightweight solution that doesn't require saving a PNG file?

What Taddeus suggested above is possibly the best way to do it. You aren't creating a .png image: the string that you pass to drawToImage() is just a virtual path.

As a matter of fact, internally this doesn't even create an HTML <img> element, but a <canvas> element, that is just as big as it needs to be to contain the thing you're drawing into it (doing so uses a bit less memory and is much quicker than creating an <img>). This canvas is not added to the DOM, it's just an off-screen image effectively.

In other words, you can give your image (or rather off-screen canvas) any name you like, and it doesn't get saved anywhere to disk. However it stays in WADE's asset manager until you explicitly unload it, and you can use it to create sprites and animations.

You can also draw multiple things into the same image, calling drawToImage for several Sprites and TextSprites, using always the same image name. There are also other parameters to customize your drawing, if you have a look at the documentation.