Firstly @NotDonna I agree with a PP who says subjects like sociology etc will be less likely to build on the GCSE (certainly in the way MFL or maths do; an A level German student, for example, is pretty much expected to be on top of verbs, vocab, genders, prepositions as these will not be retaught).
For subjects like you mention, I would say the key thing is that she has studied essay-writing subjects like history or Eng lit and has those skills – which it sounds like she has, so she should be OK there.
PE "not being of a high enough standard for A level" btw – my DS took A level PE offering football and he simply played for a local club; mate of his offered athletics and was at club and county level, so not amazing. But if the science is missing then that's a concern - DS said he was doing biology and biology! (which suited him btw).
I would be slightly concerned tho about her choices; is she thinking of uni? If not, no worries, but if she is, be aware that she is closing more doors than she needs to, as none of those subjects are needed to study the correlating subject at uni, whereas (for example) Eng lit is. Is she likely to drop one after a term or so? No need to take four A levels. You mention maths – there is quite a bit in A level psych, but that's fine as long as her GCSE maths grade is a 6/7. Psych A level anecdotally is often dropped by students who find it much dryer than they thought it would be. Would she add Eng lit to the mix as a familiar subject she is good at?