I love FMA:B just as much as the next person, but something that does bother me just a little bit in the switch from manga to anime is how they almost erase how gentle and kind Riza is with the kids.
Like these two moments with Winry and Al, they were completely taken out of the show, and while her moment with Winry doesn't hold much weight compared to her moment with Al, it still takes away from the fact that they were showing Riza's gentle side - which rarely gets shown in the anime.
I think her moment with Al definitely needed to make the show, not only does it foreshadow what is about to happen with Lust, but it's one of the first times that someone other than Ed reassures Al that he's important to what they're doing and not just important to Ed. And shows that she is confident in and trusts his abilities enough to depend on him, which Al probably needed to hear.
Coupled with Riza gently touching his chest plate, and Al's embarrassed little head rub, I think adding this moment would've only made Al's speech about not wanting to feel powerless when people die when they could've protected them even stronger.
Then with Ling and Lan Fan, the moments are smaller, but Riza is just as kind and gentle. It barely takes anything for Ling to convince her to stop and get Lan Fan, even when they are going full speed through the middle of a city, Bradley is looking for Ling and Lan Fan, and they have a homunculus tied up in the back of Riza's car.
Even when Riza is helping Dr. Knox clean up Lan Fan's amputation, in the manga, she's just gentler.
Compare this to Lan Fan having the rag in her mouth instead of Riza holding on her head, making sure Lan Fan is covered, and even the way Riza holds her shoulders is different.
And when they are piling up in the car to get away from Gluttony, in the anime they had Al take the time to ask Riza to take care of Lan Fan, which was so unnecessary. In the manga Riza just does it.
While Ed and Roy are arguing, Riza just says "Here, Lan Fan." then climbs in the back with her and cradles Lan Fan's head in her lap. None of these are much different from what they do in the anime, but I think it's enough to take away from showing Riza's soft side, especially her soft side to the younger characters.