When dealing with a headache, try boiling one cup of apple cider vinegar and one cup of water in a pot. Pour into a heat proof bowl and put on the table or other safe place that you can lean over the bowl and cover your head with a towel. Inhale the steam for a few minutes to bring some relief.
The warning on mine says not to use prior to 4 months of age. My son was in his Jolly Jumper from 3 months. The directions of use are that if they can confidently hold up their head then they are fine.
Remember, some babies skip crawling. But if your baby hasn't shown any progress in becoming mobile (whether it's bum scooting, rolling to her destination, or crawling) by 12 months or by the time she's a year old, or if she tends to drag one side of her body while crawling, it's best to consult the pediatrician.