She ran away from a brute of a husband who was in the habit of beating her.

Being myself a Picard born, I was always very fond of the Artesian women, and it is only a step from Artois to Flanders; she came crying bitterly to her godfather, my predecessor in the Rue des Lombards; she placed her two thousand florins in my establishment, which I have turned to very good account, and which have brought her in ten thousand." "Bravo, Planchet." "She is free and well off; she has a cow, a maid servant and old Celestin at her orders; she mends my linen, knits my winter stockings; she only sees me every fortnight, and seems to make herself in all things tolerably happy.
"And indeed, gentlemen, I _am_ very happy and comfortable," said Truchen, with perfect ingenuousness.
Porthos began to curl the other side of his mustache.

"The deuce," thought D'Artagnan, "can Porthos have any intentions in that quarter ?" In the meantime Truchen had set her cook to work, had laid the table for two more, and covered it with every possible delicacy that could convert a light supper into a substantial meal, a meal into a regular feast.
Fresh butter, salt beef, anchovies, tunny, a shopful of Planchet's commodities, fowls, vegetables, salad, fish from the pond and the river, game from the forest--all the produce, in fact, of the province.
Moreover, Planchet returned from the cellar, laden with ten bottles of wine, the glass of which could hardly be seen for the thick coating of dust which covered them.

Porthos's heart began to expand as he said, "I am hungry," and he sat himself beside Madame Truchen, whom he looked at in the most killing manner.

D'Artagnan seated himself on the other side of her, while Planchet, discreetly and full of delight, took his seat opposite.
"Do not trouble yourselves," he said, "if Truchen should leave the table now and then during supper; for she will have to look after your bedrooms." In fact, the housekeeper made her escape quite frequently, and they could hear, on the first floor above them, the creaking of the wooden bedsteads and the rolling of the castors on the floor.