You may well be my stepsister, but you mean more than just that to me. Our bond runs deeper and that’s why you’ll always be my soul sister. Happy birthday.
The way you welcomed me into your life will forever be the most heartwarming experience for me! You will always be a true sister to me, stepsis! Happy birthday!
My beloved twins, there is no other brother and sister quite like you both. You make everyone happy just by being with you. May you have a great birthday!