Missing/wrong credits?

There seems to be a couple missing credits, and one that is wrong.

1. Who is Frank's spinster sister? Kitty called her Ida to her face, and then Kitty and Shirley refer to her as "Aunt Ida" when they reunite when Shirley has grown up.

2. Who is Shirley as a young girl, about 4 or 5 years old?

3. The credit for the "Irish Eyes" singer says it's Carl 'Alfalfa' Switzer, but it goes to this entry with a single credit - http://www.imdb.com/name/nm8031456/ when I would think it would go here: http://www.imdb.com/name/nm0842813 There can't be two of them, can there? If this is a mistake, then this film would be his first screen credit by two years.

The first two would take some research into studio records I would imagine. The third one is a simple correction, I think.