What information does the maid impart to Kate about Marlow's view about her, her father, and their house in She Stoops to Conquer?

The maid in Oliver Goldsmith's comedy of manners She Stoops to Conquer, Or, the Mistakes of an Evening—first appears in the play in the third act. She tells Miss Hardcastle (also known in the play as Kate) that her suitor, Marlow, believes that Kate is a barmaid, based on the dress she was wearing when she recently passed by him:

MAID: But what is more, madam, the young gentleman, as you passed by in your present dress, asked me if you were the bar-maid. He mistook you for the bar-maid, madam.
MISS HARDCASTLE: Did he? Then as I live, I'm resolved to keep up the delusion. Tell me, Pimple, how do you like my present dress? Don't you think I look something like Cherry in the Beaux Stratagem?

The Beaux Stratagem, written by George Farquhar, was a popular comedy first produced in 1707 but was still known and popular when She Stoops the Conquer was written in in about 1773. In The Beaux Stratagem, Cherry is the innkeeper's saucy daughter.
One reason that Marlow might take Kate for a barmaid, aside from her plain dress, is that he's been led to believe by the ne'er-do-well prankster, Tony Lumpkin, that the Hardcastle's home is an inn, and Tony sends them there to find lodging for the night:

TONY: What if you go on a mile further, to the Buck's Head; the old Buck's Head on the hill, one of the best inns in the whole county? . . .
LANDLORD: (apart to TONY) Sure, you ben't sending them to your father's as an inn, be you?
TONY: Mum, you fool you. Let THEM find that out.

Marlow and Kate had crossed paths previously in the play when Marlow first came to her home and they spoke to each other. Kate was well-dressed at the time, however, and Marlow has great difficulty talking to well-dressed, well-bred women and barely looked her in the face:

MISS HARDCASTLE: Was there ever such a sober, sentimental interview? I'm certain he scarce looked in my face the whole time.

When Marlow saw her again, she was plainly dressed:

MISS HARDCASTLE: And are you sure he does not remember my face or person?
MAID: Certain of it.

Kate decides to play the part of a barmaid, "to keep up the delusion," to get to know Marlow better:

MAID: But what do you hope from keeping him in his mistake?
MISS HARDCASTLE: In the first place I shall be seen, and that is no small advantage to a girl who brings her face to market. Then I shall perhaps make an acquaintance, and that's no small victory gained over one who never addresses any but the wildest of her sex. But my chief aim is, to take my gentleman off his guard, and, like an invisible champion of romance, examine the giant's force before I offer to combat.

The maid has some doubts:

MAID: But you are sure you can act your part, and disguise your voice so that he may mistake that, as he has already mistaken your person?

But Kate assures the maid that she can act the part, and speaks a few phrases in a barmaid's accent ("the true bar can't"):

MISS HARDCASTLE: Never fear me. I think I have got the true bar can't—Did your honor call? Attend the Lion there. Pipes and tobacco for the Angel. The Lamb has been outrageous this half-hour.

Marlow enters, Kate assumes the part of the barmaid, Marlow falls for her barmaid act, and the antics of mistaken-identity begin.