An interesting piece in yesterday's Financial Times on grandparents (in the main, grandmothers) who find themselves an essential part of their children's (mainly daughters) childcare arrangements.  This is, often, at the expense of their own career, which may have just been taking off again. The lead story (for those of you who aren't behind the FT's paywall) is about an accountant, Tracey Conway, who had moved up from 2 days a week to 5 days - and has now gone down again to help look after her grandson, as her daughter pursues her career at the bank.  She finds much to be happy about it, especially her strong link with the…