For a psychology degree sociology A-level is good preparation, some universities (like Bath) actually prefer it. If you enjoy it and can get a high grade in it then it should be fine.
Generally speaking, English Lit is a very strong subject, Economics quite a strong subject, psychology somewhere in the middle and sociology a bit lower and often considered (especially on tsr) as 'soft'. However, you are applying for a psychology degree where they often consider psychology to count as a science A-level, and also consider sociology A-level to be worthwhile - so for your chosen degree they are good subjects.
Some unis prefer to see a natural science (biology, chemistry, physics) and/or maths (due to the high statistics content of a psychology degree) as well as a social science. If you could do one of those it would certainly strengthen your application and help you later in the degree - especially biology if you can do it. But if you do not think you would get a good grade then stick with your choices, they are perfectly ok for psychology at most unis as long as your science GCSEs are good.