I cannot agree 100% on the age issue here. Only because I think if it's a role in a quality film, then age or beauty will not make or break it. Tilda Swinton won supporting actress for Michael Clayton - she is not your typical beauty and she is "older". (more of Tilda's awards http://www.imdb.com/name/nm0842770/awards)

There are a boat load of "older" actress' not botoxed out, that have been acknowledged in the US Market.

I believe AMD would only consider quality projects.

But if we are talking a film based around twenty somethings, then you would be stupid not to cast the appropriate age. Hence why AMD taking on the role of Lennon's mother makes perfect sense.