you need to obtain a readers ticket for which you need a couple of forms of id that include your address (for looking at original records) but you can look at the index to post 1837 births deaths and marriages in your local library, no need to go to Kew. they don;t issue copy certificates there and they don't hold the original regsiters 9even if they did you could not look at them)
They do not hold parish registers, these are at your County Record Office.
the records you research at kew are military, court records, immigration records, and lots more besides.
You need to have a closer look at the archive holdings before you go to be sure you will have a worthwhile visit, i am not 100% sure, but i don't know what research your daughter has done, but i don;t think she would need Kew at this stage, and Kew is for looking at original documents which i don;t think minors are allowed to handle, there is not much to look at on a PC that isnlt available elsewhere.
I havn't been to Kew for 14 years but i am pretty up to date on the archive holdings, if i am wrong in any way i am sure someone will correct me, and apologies if i am incorrect..
http://www.nationalarchives.gov.uk/familyhisto ry/