Heather's rhymes with:
heathers, birdfeather's, birdfeathers, feathers, get-togethers, gethers, heathers, leathers, nethers, smethers, tethers, togethers, weather's, weathers
Heather's sounds like:
haters, hatrick, hatteras, headdress, headdresses, headers, headrick, headwaters, heaters, heathers, heathrow's, hedrich, hedrick, heidrich, heidrick, heterosis, heterozygous, hetrick, hettrick, hitters, hooters, hydras, hydrick, hydro's, hydrous, hydrox, hydroxy