Thank you for your query.
over a joint is very painful and a person restricts movement to reduce pain. Moreover a 2 year old daughter is bound to create a fuss over it. I suggest you apply ice pack over the swelling two-three times a day and observe for the next 24-48 hours. You may also give her a mild analgesic
in the form of syp. paracetamol
5 ml. three to four times a day. If the swelling increases or the child finds difficulty in walking then a consultation with a doctor is required.
I hope I have answered your query to your satisfaction.
Wishing your daughter an early recovery.