I don't think you'll be happy. They don't mention astro use in the blurb. If they don't do that, then you can be pretty sure they are not recommended for that work - any slight chance they could be and the advertising would surely be saying it!
Most astro binos at 20x mag are 80 or greater aperture so this is small - another hint they are designed as daylight binos. However, I cannot see the "giveaway" red ruby objective lens coating in the photo.
And absolutely, even for daytime use, you need to steady these on a tripod or some other way - hand-held will be very difficult - image very unsteady. I'm sure that a 6yr old and even 10 yr old will not be able to hold them steady - I cannot hold 20x steady enough to really look at anything.
Also, at 20x magnification, you need to be fairly experienced to place an object in the sky in the field of view. It's not as easy as it seems - that why telescope finders are typically 8x or 9x.
I agree, try to find something that is said to be for astronomical use in the 9x or 10x range.
Sorry to be a wet blanket!
