My Year 1 child is using: The Burgess Bird Book, Christian Liberty Nature Reader 1, Handbook of Nature Study, occasional fun experiments, gardening, collections as interested/wanted, nature study, etc… I really feel that it is enough.
Maybe once per month you could have science saturday: freeze water to ice and thaw back, play with magnets, plant a small garden, look at rocks, talk a bit about the sun/moon/stars and how they move (demonstrate with flashlight and globe how day/night comes about), etc…testing at that age is going to be really basic stuff. No more than 5-10 mins needed at a time to cover this stuff.
Relax, mom! 🙂