Why don’t you just take them back to the store, or have you already washed them?
Or why not wait and see, whoever told you might be wrong again?
Or dress your baby girl in boys clothes, better than dressing a boy in girls clothes and I don’t think you will warp her at this age.
Other Mothers will pay you for baby clothes…although they pay VERY little
You can take them to the Salvation Army, some thrift stores will give you money in exchange for clothes, or at least a tax write off.