a)
Gertrude Rosalind &
Maud Etheldredab)
Amanda Gertrude &
Lilian Maudc)
Gertrude. It has always been a GP of mine. No strong feelings about
Maud.
d)
Maude looks more complete and elegant IMO.
e)
Trudy.
Gertie sounds like a modern nickname that feels a bit forced.
Trudy comes more natural.
f) I'd assume
Gertrude was older because it's more common (or more heard of) than
Maud, and I tend to expect the older sibling to have the more common name (parents tend to be more liberal / wild with younger kids' names).
