1yo refused to drink water

My 1yo girl just reduced from 4 to 3 formula feeds a day to encourage her to eat more. However, she refused to drink any water and gets badly constipated. We tried using her cup with straw, my cup with straw, milk bottle, she just struggles to get away without tasting. We also tried giving her a tini cup to sip but she chokes on the water. Tried sippy cup, refused to touch. Warm, cold, fruity water, all nope. Only time she drinks some is when I use soup spoon to feed, but she gets bored after awhile too. Help!!😭