Oh, Yoite. That explanation from Tidus doesn't even surprise Madoka, considering her initial conversation with Yoite.. Him going off on his own since he thought that was the intention sounds exactly like the kind of thing he might do.

So she feels rather grateful that Tidus spotted him in time and brought him over to them.

"Of course. Romeo and I are so used to these missions, helping out a new person shouldn't be hard, right?" She glances at Romeo at that last part, giving him a smile, before looking at the two older guys - particularly at Yoite. "As long as you don't mind being around us!"