Sleep Training

I am trying to sleep train my 16 month old especially that i just gave birth to her sister. So i have a newborn and a 16month old to deal with.

We sleep trained my 16month old a month ago and she became an excellent sleeper, we used a gentle sleep training method (there was some crying involved but nit like crazy) and it only took 2 days for her to sleep on her own and continue sleeping all night long, until she caught a cold and we had her sleep with us for a week so she regressed as she got used to sleeping with us.

When i came to the hospital to give birth to the second baby we left my daughter with my in laws for 3 nights during which she slept with my sister in law in her bed and was not following any of the sleep rules we have at home (which i am totally ok with) but then we get a call from my sister in law and my mother in law stating that how can we ever let my daughter cry herself to sleep and how cold hearted of a mother i am (they did not state it this harsh but it was implied) that i do not sleep in the same room as my daughter and how she needs to feel love and not be alone scared in her room...

I am deeply hurt and feel no support and started questioning if i am a cold hearted mother for sleep training my baby even though that worked best for our family. Now that we are going back home from the hospital after i delivered i know for a fact that my first born will have a hard time sleeping and we will need to sleep train her again but i am conflicted.