In HP and the Order of the Phoenix Dumbledore sends Hagrid and Maxime off on a mission to try to win the trust of the remaining giants. It seems that large amounts of enforced proximity and shared hardships has worked its usual magic;

‘Madame Maxime went with you, then?’ Hermione interjected. ‘Yeah, tha’s righ’,’ said Hagrid, and a softened expression appeared on the few inches of face that were not obscured by beard or green steak. ‘Yeah, it was jus’ the pair of us. An’ I’ll tell yeh this, she’s not afraid of roughin’ it, Olympe. Yeh know, she’s a fine, well-dressed woman, an’ knowin’ where we was goin’ I wondered ’ow she’d feel abou’ clamberin’ over boulders an’ sleepin’ in caves an’ tha’, bu’ she never complained once.’

Note also that much of her grumpiness in the HP:GoF seems to centre around her unwillingness to admit to being a giantess. By HP:OOtP it appears that she's come to admit (at least to Dumbledore and his close allies) that she has giant heritage.

Toward the end of HP and the Goblet of Fire, Hagrid and Madame Maxime are called to Dumbledore's chambers and given the details of their mission to try to win the trust of the remaining giants. It seems that the prospect of their upcoming quest is sufficient to make her at least pleasant toward him:

‘Minerva,’ said Dumbledore, turning to Professor McGonagall, ‘I want to see Hagrid in my office as soon as possible. Also – if she will consent to come – Madame Maxime.’

then some weeks later...

‘Bin havin’ a cuppa with Olympe,’ Hagrid said, ‘she’s jus’ left.’ ‘Who?’ said Ron, curiously.
‘Madame Maxime, o’ course!’ said Hagrid.
‘You two made it up, have you?’ said Ron.
‘Dunno what yeh’re talkin’ about,’ said Hagrid airily, fetching more cups from the dresser

As to the outcome of this, we learn in HP:OotP that large amounts of enforced proximity and shared hardships has worked their usual magic;

‘Madame Maxime went with you, then?’ Hermione interjected. ‘Yeah, tha’s righ’,’ said Hagrid, and a softened expression appeared on the few inches of face that were not obscured by beard or green steak. ‘Yeah, it was jus’ the pair of us. An’ I’ll tell yeh this, she’s not afraid of roughin’ it, Olympe. Yeh know, she’s a fine, well-dressed woman, an’ knowin’ where we was goin’ I wondered ’ow she’d feel abou’ clamberin’ over boulders an’ sleepin’ in caves an’ tha’, bu’ she never complained once.’

Note also that much of her grumpiness in the HP:GoF seems to centre around her unwillingness to admit to being a giantess. By HP:OotP it appears that she's come to admit (at least to Dumbledore and his close allies) that she has giant heritage.

In HP and the Order of the Phoenix Dumbledore sends Hagrid and Maxime off on a mission to try to win the trust of the remaining giants. It seems that large amounts of enforced proximity and shared hardships has worked its usual magic;

‘Madame Maxime went with you, then?’ Hermione interjected. ‘Yeah, tha’s righ’,’ said Hagrid, and a softened expression appeared on the few inches of face that were not obscured by beard or green steak. ‘Yeah, it was jus’ the pair of us. An’ I’ll tell yeh this, she’s not afraid of roughin’ it, Olympe. Yeh know, she’s a fine, well-dressed woman, an’ knowin’ where we was goin’ I wondered ’ow she’d feel abou’ clamberin’ over boulders an’ sleepin’ in caves an’ tha’, bu’ she never complained once.’

Note also that much of her grumpiness in the previous book seems to have been connected to her unwillingness to admit to being a giantess. By the second book it appears that she's come to admit (at least to Dumbledore and his close allies) that she has giant heritage.

In HP and the Order of the Phoenix Dumbledore sends Hagrid and Maxime off on a mission to try to win the trust of the remaining giants. It seems that large amounts of enforced proximity and shared hardships has worked its usual magic;

‘Madame Maxime went with you, then?’ Hermione interjected. ‘Yeah, tha’s righ’,’ said Hagrid, and a softened expression appeared on the few inches of face that were not obscured by beard or green steak. ‘Yeah, it was jus’ the pair of us. An’ I’ll tell yeh this, she’s not afraid of roughin’ it, Olympe. Yeh know, she’s a fine, well-dressed woman, an’ knowin’ where we was goin’ I wondered ’ow she’d feel abou’ clamberin’ over boulders an’ sleepin’ in caves an’ tha’, bu’ she never complained once.’

Note also that much of her grumpiness in the HP:GoF seems to centre around her unwillingness to admit to being a giantess. By HP:OOtP it appears that she's come to admit (at least to Dumbledore and his close allies) that she has giant heritage.