'13'was a musical starring Elizabeth Gilles (hence my guess 'Eliza'). The number 13 may also be construed as the 'sequel'to the number 12. Flawed reasoning, no doubt, but it was an attempt.
Only have 19d/25a to do. "Much of 11 on two Scots rivers points to set of tunnels" I have the 25a part of it, there is a tunnel of that name in Scotland and I think it is also the name of an 11a. But the 19d part has me stumped. Any ideas?