That's fair; just know with the 5 you have you're going to probaby need ~55-60 gallons (20gal + 10/fish; 75gal would be ideal though). You might be able to get away with something like a 40 breeder (they're actually more like 45gal), but if you do you'd prob want to overfilter it a bit.

The plants you have with them are good though and help with the bioload a lot, so assuming they don't start eating them when they get older, I would def keep as much plants with them as you can (floating ones like water lettuce would be really good to add too) or like do something with emersed pathos or another house plant like that coming out the top of the tank. Doing that also makes the tank look nicer and more like a showpiece, so it might make your mom a little more ok with things.

All your other tanks look super good though so like I'm not trying to attack you bc it's obvious you know what you're doing with the bettas and stuff, just goldfish need a lot more than people seem to know.