Inevitably she would forget the time, remaining entirely oblivious of such mundane things as meals.

Then she would be sharply recalled to the fact that she had committed an unforgivable sin by receiving a stately message from Lady Gertrude to the effect that they were waiting lunch for her.
On such occasions Nan sometimes felt that it was almost a physical impossibility to enter that formal dining-room and face the glacial disapproval manifest on Lady Gertrude's face, the quick glance of condolence which Isobel would throw her--and which always somehow filled her with distrust--and the irritability which Roger was scarcely able to conceal.
Roger's annoyance was generally due to the veiled criticism which his mother and cousin contrived to exude prior to her appearance.

Nothing definite--an intonation here, a double-edged phrase there--but enough to show him that his future wife fell far short of the standard Lady Gertrude had in mind for her.

It nettled him, and accordingly he felt irritated with Nan for giving his mother a fresh opportunity for disapprobation.
They were all unimportant things--these small jars and clashes of habit and opinion.

But to Nan, who had been used to such absolute freedom, they were like so many links of a chain which held and chafed her.