If you can handle it why not?
However, considering you are in year 10, you do not know what a-levels you will find easy or hard. Subjects change. I found A-level Further Maths much easier than GCSE Maths (sounds really silly, but it happens). I’ve been told languages are more literature based too at a-level, so you may not enjoy it/be as good as you think.
Also, I think Ivy’s care more about extra curriculars than extra a-levels. I would say focus on 4 a-levels and then bang out some ecs (team sports etc).