She'd use the filled up barrels over the following weeks to continue watering her potted plants, citing that the water had more 'good stuff' for plants than the water that comes out of the hose. And don't worry, she kept all of her collected rainwater covered so it never bred mosquitos.
You might not have a huge garden, but if you have a chance, move some of you indoor plants outside, or some that might be covered by a porch to catch some of the rainwater and maybe throw out a couple of bowls or buckets to use up over the next couple of weeks. It might not be as fancy as some of the rainwater collection systems out there, but you can start today and your plants will thank you.
See my gramma's garden (and the results of rainwater and a lot of hard work) right here.