Recomended bias/fabric tape for a hem

This might be a dumb question but I'm newish to sewing clothes (I can embroider and I know basic practical stitches) and I wanted to do a quick dirty fix on hem on my kiddo's Princess Peach cosplay. Is there a bias or fabric tape that folks recommend for a temporary fix that will wash off or something when I'm a little more confident in my skills? She is growing like a weed so the dress was bigger so she could have it for longer. Sorry again if this is dumb or not like a real cosplay question but I'm just a nerd mom trying to make a kiddo happy! Any and all advice appreciated!