Perhaps giving her more foreplay - at least min 30mins till
she's sexually aroused, than as you lick her (if you're open to the
idea) till you get her wet enough, than you finger her first, but
for 1st time you insert, do it gradually while she's relaxed, thus
it will the pain she will not close up her walls inside which bar
you from entering (meanwhile you lick her to give her more pleasure
- divert her attention elsewhere in this case, more orgasm) than
you can slowly finger her till she like it, than you enter
her.
Lol.
For alternatives, or better ideas, PM me privately as this is
afterall a public forum with some people still underage, thus it's
not convenient to pose the details here.