It's parsing for me, I'm afraid.
3D I'm ten and likE ELephants to some extent (3). Why should EEL belong to 'I'm ten'?
10A Evasive son gets slap round mouth, Queen involved? (8) SLIPPERY = evasive, son = s, Queen = er. I just can't see how 'slap' fits in.
23D Worry that daughter's wearing a red outfit (5). Is a CADRE a red outfit?
Thanks in anticipation.
I thought his might be 'dread'. The way I parse it is: worry is the definition arrived at by D(daughter) followed by an anagram of 'a red'. The anagram indicator being the word 'outfit'