you were in your room when you heard your mother is transforming into her black horse form

Emily felt her entire body stiffening preventing her from doing anything the curse gripped her strongly preventing her from trying to protest her fate deep inside she knew she brought this curse upon herself for foolishly meddling with occult ritual despite her wariness & trepidation about what was to come while she felt the magical tendrils of power course through her body she could not deny the almost bemused fascination about what was to unfold still trembling in place she could barely breath while she felt her entire body start to grow & swell larger she knew that her meager size was inappropriate for what was needed and could only bear with the sensation as her body enlarged already she could feel her skin start to crawl while beneath the surface muscles & bones expanded in mere moments she had grown a head taller with muscles starting to visibly swell outward she could only feebly protest at the feeling of the straps of her nightgown starting to press against her swelling body already the material was starting to plaster itself tightly against the burgeoning form that was growing outward while she still retain a feminine form at the moment her nightgown was looking incredibly scandalous hugging the increasingly muscular frame already the bottom hem of the gown was climbing upward to reveal more her thickening thigh & swelling rear as the change progress her red hair too started to thicken once cropped short it started to spread outward brushing down her shoulders but that was hardly as distracting as the sensations of the ears moving past the growing hair the ears were stretching outward & widening changing in their form to something more appropriate for a horse her face twisted both in shock at what was happening but also as her nose changed too her nostrils snorted loudly to her surprise while the noise started to thicken & spread further over her face this was followed by her mouth cramping up with her teeth changing into thicker form more suitable for an herbivore she felt her brow started to thickened & jut outward with her facial structures already starting to shift into a more equine shape ahead of the rest of her swelling body the straps on her nightgown snapped open unable to hold down the massive bulging muscles of her body while her shoulder broadened inadvertently flexing the incredible musculature that now rippled across her growing body she could hear the sounds of more tears erupting across the gown but what more was how the tearing garment revealed the thickening mat of black fur that was quickly covering her body the top of the nightgown spilled open allowing her breasts press outward into the open but her embarrassment at their exposure quickly passed with a gasped the musculature of her chest pressed outward & swallowed up the bosoms her head now almost brushing her ceiling she could only look onward as the changes started to strip her body of their more humanoid shape her stomach gurgled with the organs beneath rearranging themselves while her torso remolded itself & spine shifted too unable to properly stand bipedal anymore she fell forward partially onto her bed her posterior now pressed against the window continued to swell larger much to her embarrassment at the sensation she could only let out a weak choke when a crimson tail came ripping out beneath the bottom of her nightgown arching her back as she felt the tail emergence the last of the gown ripped apart not that there was anything left that would be embarrass to show with her body now more thoroughly equine except a few portions her hands could not grasp at anything on the bed the nails having already thickens into a different form the palm of the hands swelled larger to swallow up her fingers to leaving only the nails at the tip to solidify together into hooves stamping against the ground below her foot too have also went through a similar metamorphisms she felt her face stretch out with her nose & mouth pushing outward as her eyes turn red