@Samesdaynight no one can tell you what your DC's school will do, so it’s best to ask them.
IME in general pretty much all schools set for maths and many set for English, certainly at GCSE (some schools for example will study different texts in different ability groups). Everyone takes English so, although there is no tiering, there are enough students to set.
For science, some schools offer triple to a specific group based on ability (my DCs' school did this) so those students study the triple content in the same lessons that others do double – so a higher ability level is needed. In my DCs' school that group were in lessons together for all subjects because of the way the timetabling worked. They then took 10 not 9 GCSEs.
But increasingly schools are offering triple as an option – so with extra lessons – which means that all abilities can take it (tho obvs that takes up an option slot). It's possible to sit F level of science so triple in this way may well be fine for a weaker candidate, esp if they are stronger in one science. If the triple option is offered, groups may or may not be streamed.
For option subjects, as PPs note, it depends on the size of the school. A five-form entry school is perhaps 650 students across KS3 and 4 which is a very small secondary; a more average size is closer to 1200 students and 8-9-10 forms (a big school is 2,000 students), which may make setting more likely (for example, as many as half the cohort may choose history so the group of 100+ students may be set. But they may not.)
My subject is MFL and one year we had 60 opting for German so we had a top set of about 26, a middle group of about 20 and a lower set of 14 or so who were all targeting the foundation paper. But some years that wasn't possible due to timetable constraints.
Basically you need to ask your school – but as you can see, many permutations are possible. Apologies for the essay!