Add olive oil and set the Instant Pot to "sauté" setting. Add the onion, carrots and celery, cooking for 4-5 minutes or until the onion is translucent.
Add the rice, garlic, thyme, rosemary, salt and pepper, cooking for another minutes.
Pour in the chicken stock and add the chicken. Close lid and turn vent to "sealing." Set Instant Pot to "manual" on high pressure and set for 10 minutes. Allow it to naturally release for 10 minutes, then quick release.
Remove the chicken and shred with two forks before adding back to the soup. Stir in the lemon juice and taste, adjusting for seasoning if needed.
Notes
Use pre-shredded rotisserie chicken to make the soup even quicker.
Replace dried herbs with fresh herbs if needed. Just triple the amount.
Use quality low-sodium chicken broth as it contributes to the flavor. You can also use chicken stock which gives the soup more mouth feel.
If the soup is too thick for your tastes, just add some extra broth.