A Great Question

I purchased souns for my infant daughter when she was a few months old. She began making the sounds of the first letter almost immediately after introducing it (somewhere between 6 mos and 1 yr). I introduced a few more, and she said those as well. It was so amazing.

She had about 5 letter sounds down before the age of two. Funny thing is, she was speech delayed. Didn't say Mommy until about two years old (Said Daddy a little earlier).

I have an older son in kindergarten, so my daughter is exposed to a lot of books and videos with letters. Due to this, she will sometimes say the name of the letter instead of the sound. It has also become increasingly difficult to teach her the new sounds. The e is hard for her to say...it sound like the i. The i sounds like the e. Should I skip these and continue with other letters?

Now that she is mobile (didn't walk until almost 19 mos) and talking and able to play with a lot more stuff, she isn't really interested in her souns letters as much. I have to catch her in the right mood. Do you have any tips to keep this going?
J