Currently the other Humanities subjects don't count towards the Ebacc, although there is pressure to include these later down the line. At the moment it is confined to History or Geography.
Offering double Maths. to the top sets is fairly standard practice. Some schools allow those students to do the traditional Maths GCSE in Y10 and Advanced Maths in Y11.
OP, I'd strongly advise your DD to pick either History or Geography. Both might be too much alongside her very academic diet, but as long as she keeps Spanish and takes one Humanity subject, I think she will be fine. It might also be worth finding out whether she will have to do Core Science as well as Triple Science and therefore a lot of science lessons in a week! Not from the perspective of dropping Triple Science as an option I must stress, but more from the perspective of trying to balance her timetable with more arts/creative options so that she doesn't get too bogged down with academia - and gets a more rounded education.
Whether your school is providing for the EB or not, luckily it is a National standard and if your DD gets A*- C in the Ebacc subjects, she will have achieved the Ebacc standard by default.
As you will have seen from this thread, some schools are working hard on their capacity to provide EB subject options to students who will benefit and can manage that academic diet, some schools have decided not to do so, or lack the capacity to offer more students the option of taking Ebacc subjects. There is understandable resistance from teachers who teach non-Ebacc subjects, because it makes their positions vulnerable if there is a low take-up rate for their subjects.
However, whatever your political beliefs, the Ebacc is very similar to the former School Certificate, or Matriculation. It is neither avante-garde nor novel to offer a broadly academic diet to students with the aptitude and ability to study those subjects. Regardless of any propaganda you might hear about Universities and Employers valuing BTECs and GCSEs in Media studies and Performing Arts as being of equal merit to qualifications in academic subjects, in an Employer's market and against a backdrop of shrinking F/E funding, it is simply not true. In some jobs and at some universities, high-grade GCSEs in academic subjects will always be more valuable. The Russell Group has in fact produced a guide where it is clear that those universities do take into account GCSE subjects/results alongside other factors in determining to whom they will offer places. UCL for example, insist on a Language GCSE for any course.