I would recommend hands down go for s23 in big billion you are getting it for 37-39k!(save the rest of the money for your sister) I own one and these are honest reviews! Its more than a year n half.
Camera pics are more towards natural or realistic side.
There are reasons not to buy any of the phone you asked
Oneplus -After the universal havoc of green line issue,OP is now offering motherboard dead scenes post software update
Moto - They are good value for money but software update has always been a challenge
Nothing - May be a thing for enthusiast people, considering your sister is just like mine all they want is a nice camera phone
Another option is iphone 14 to consider
Both s23 and i14 take similar photos only thing that differentiates is ..iphone pics are boosted and ready for social media where as s23 is more towards keeping it real. Depends on your choice now
Note- Flagships with 6.1 screen dont have great battery life. Expect a decent 6-7 hrs SOT with normal usage