depends what you think g&t means and what you think 'eligibility' will entitle her to?
any 'labelled' g&t child in any of the five schools my dcs have been in has been given the same opportunity as any other child in the school - ie, appropriate differentiation of curriculum activities. there is no additional funding.
realistically, your dd sounds as though she has a high reading ability - does her comprehension level match her 'reading' skill? usually 'g&t' for reading means they are given access to reading material from higher year groups. this is tricksy in an infant school, but is usually more than manageable in a through-primary with no drama.
dd1 was assessed at ort 10 when she started yr r - she was reading c s lewis etc at home, (and a couple of pages of virginia woolf over my shoulder lol, until i told her to buzz off) and she would just swop books from other year groups whilst those at different stages used the appropriate selections.
'g&t' is just common sense really, unless the child has an extraordinarily ability which the school are unable to cater for.
there is no real 'eligibility' as there isn't anything to be 'eligible' for, unless it's putting her name on a fairly pointless list.
she sounds as though she's doing very well with her reading though. worth asking the teacher at the next parent's evening how they are supporting this love of books, but i would tend not to bring up g&t, rather talk in terms of appropriate differentiation.