She's one of Nobita's classmates that appears as a recurring character. The 2005 series seems to have introduced more minor characters, most of whom are unnamed.
From the episode 熱血！のび太の運動会, the general layout of the classroom looks something like this (only recurring characters are indicated):
[ Girl A | Girl D ]
[ × | Shizuka ] [ × | × ] [ × | × ]
[ Gian | × ] [ Nobita | Dekisugi ] [ Boy C | Boy D ]
[ × | Boy B ] [ Boy A | Boy E ] [ Suneo | Girl C ]
[ × | × ] [ Girl B | Girl E ] [ Girl F | × ]
As for her name, I'm not so sure. She's neither named nor addressed directly in the Japanese subtitled version.
All of Nobita's classmates' names seem to be on here, from ためしにさようなら:
(Either they literally have ○s in their names, or it was intentional.)
It seems that not all of Nobita's classmates signed it.
From watching other episodes, I have deduced the following:
Boy A and B are the ever-popular recurring side characters Yasuo (安雄) and Haruo (はる夫).
The characters seem to refer to the girl as "委員長 (class-rep)," so I guess she's the class rep... and it should make sense for her to sign it.
- Boy A： 鈴木安雄 (see above)
- Boy B： 大川春夫 (see above)
- Boy C： Either 山川○男 or 吉田○夫?
- Boy D： 山田○介
- Boy E： 佐藤正美 (recurring character)
- Girl A： 近藤○キ (It's the class-rep?)
- Girl B： ???
- Girl C： ???
- Girl D： 田中悦子 (recurring character)
- Girl E： 大田○司
The episode ツルリン！先生がとまらない mentions 4 more classmate names:
It's possible that the two girls with missing names are named here... or they could be some other classmates/people altogether.