Toddler wanting to nurse again?

My 22mth old ds has shown interest in nursing again/esp when I nurse my 9mth old dd. He was ebf up until 7 or 8mths or so, when i had to give him my freezer stash of milk as my milk dried up to nothing in the middle of my preg and he would nurse but wouldnt produce wet dipes at all. When dd was born he was 14mths and not interested in nursing. And hasnt been until now. I did want to tandem nurse and felt guilty for not being able to nurse him longer than i could