Hello, I am wondering if it's now ok to give my 19 month old a blanket to sleep? She has a blanky that helps her get to sleep, but I sneak in later and take it off her for the duration of the night. I'm doing this because of the SIDS recommendations that there be nothing else in the cot. But I'm wondering if this is for babies under 12 months? Do I still need to be doing this?

Red Nose recommendations are specifically related to babies who are less than 12mths of age, although sleep accidents can occur with older children.
Red Nose recommends following the soft/loose bedding guidelines while ever the child is in a cot.

Older babies in a cot can be at an increased risk of a sleeping accident by using pillows and bumpers as a step to climb up and fall out of the cot. It is safer to wait until the child starts to sleep in a bed before introducing a pillow or other soft bedding.
https://rednose.org.au/article/at-what-age-can-i-introduce-cot-bumpers-and-pillows

Red Nose does not recommend the use of a soft toy/comforter for babies under 7 months of age due to risk of suffocation & overheating, & has the following information.

Keep soft toys out of the sleeping environment for babies under seven months of age because they may cover the nose and mouth and interfere with breathing.
The risk posed by suffocation by the presence of soft objects in the baby’s sleeping environment outweighs any benefit to the baby from a soft toy. It is therefore advised not to place soft toys and other soft objects in the cot for babies under seven months of age.

Seven-month-old babies are more likely to explore objects in their sleeping environments than younger babies. Some babies over seven months of age may appreciate a small object such as a soft toy to provide comfort and connection (transitional object) during times of separation from their parent.

Soft toys should never be placed in the sleeping environment of an infant under seven months of age.
Soft objects in the cot can be a suffocation risk. Physiological studies indicate that facial obstruction by soft bedding may lead to complete airway obstruction, and/or hyperthermia, and/or accidental suffocation by rebreathing
https://rednose.org.au/article/soft-toys-in-the-cot