Any hints to keep my nerves intact?
About a month ago DD2 (now 15 months) was sitting in her antilop high chair banging cups together as I prepared dinner. I hear a squeal of delight & turn around to see her standing on the seat. She has proceeded at repeat the feat a number of times.
We've now got a harness from a pair of reins attached to the seat but she seems to be able to get her feet up on to the seat and push upwards which is loosening it.
Any hints on how to keep her in her seat? (It's not about being finished or whatever, she seems to see it as a challenge 
She's even worse when we are out somewhere & using a cafe high chair.
Help!