Setting aside misogyny, misinformation, and general ignorance of human anatomy, which seem prevalent in many venues:
- a woman's physical height has very little to do with the capacity of her vaginal barrel, or the internal structure of her reproductive organs
- pain, including tearing, bruising, and contact with the cervical os are either the result of an unskilled male, ......, or misogyny/imagination
- having treated genital sexual trauma, most injuries of this nature are the consequence/result of forced and non-consensual sex
A woman's vaginal barrel naturally accommodates a wide range of penis sizes - without permanent change, unless the sex act damages the genitalia. That damage can come about from inexperience, lack of stimulation and lubrication, forse, or penetration by objects that create lacerations or penetrating injury.
Most of the "she couldn't walk" the next day/week/month are nonsense; the product of the male imagination. In cases where this is a fact-based consequence, the injury is the result of ineptitude or violence. Attention to arousal, lubrication, technique, and simple empathy, common courtesy, and respect don't result in genital injury.
One need only to look at porn as existence proof. There are dozens of actresses in the domain under five feet tall, with petite frames/features - these women readily engage in sex with many well-endowed men, one, to several at a time, repeatedly. They are generally uninjured as a result, and their vaginas don't permanently stretch, or otherwise change. Similarly, there are performers who engage in acts that likely cause temporary damage, or worse, long-term damage - anal or vaginal prolapse are good examples. Those are extreme practices with similar risks. Surgical correction of injuries like this are difficult, with painful and protracted recovery.
Another bit of existence proof is childbirth. The vagina, uterus, cervix, etc. all generally return to their prior state after delivery. Granted, there can be long-term changes as a consequence of multiple birth events, but these are primarily internal changes to the pelvic floor and related structure.