My 2 1/2 year old won't play independently. My wife is at her beck and call. I think it's unhealthy.?

i have 4 and 5 year old girls. i remember when i brought the youngest home the older one screamed and threw tantrums for a few weeks. she didn't want her around for a long while and constantly followed at my heels. when my youngest started walking, i tell you these two have become inseparable. also all children are so different. my 5 year old still needs our attention and our four year old LOVES to be left alone to play and do her thing weather its in daycare or at home...very different