Allan wrote to her for money when she was utterly unable to get it.

She was compelled to borrow it from Lord Ridsdale.

He lent it to her with a smile, telling her at the same time, with real gravity in his voice, that he hoped she was keeping no secret from her husband.
So the time came when she could no longer keep pace with his extravagance, when she was compelled to refuse his request.

He had lost some money in a bet over some horses.

He told her that he must have it, and she assured him that it was impossible.