He was formally introduced to them.

Miss Beecher and Miss Elsie Beecher had both, the latter very recently, reached the dignity of young womanhood, and wore long dresses.

The three boys, who were younger, were made known afterwards.
When they went into the dining-room the Canon selected the soundest of a miscellaneous collection of chairs for Hyacinth, and seated him beside Mrs.Beecher.Then the elder girl--Miss Beecher's name, he learnt, was Marion--entered in a long apron carrying a boiled leg of mutton followed by her sister with dishes of potatoes and mashed parsnips.
'You see,' said Mrs.Beecher, and there was no note of apology in her voice as she made the explanation, 'my girls are accustomed to do a good deal of the house-work.

We have only one servant, and she is not very presentable when she has just cooked the dinner.' Hyacinth glanced at Marion Beecher, who smiled at him with frank friendliness, as she took her seat beside her father.

He saw suddenly that the girl was beautiful.