ANSWER – From what I understand being the middle child is never an enviable position. They don’t have the eldest’s privilege of getting to do everything first but nor do they get the attention that the youngest usually needs. Being in the middle is often a lonely place to be.
Before we get into any magic suggestions I’d like to suggest a practical solution that might help you out a bit here. I think what your middle daughter needs is something special that belongs only to you and her, something she can claim as her own niche inside the family. Given what you talk about at the end of your question and her natural interest in herbs and oils I wonder if it might make sense to tell her a bit more about what you practise and go into a bit more detail about the kitchen witchery. Having a secret that she shares with you will make her feel special and it will help build that bond between the two of you that seems to be missing at the moment. You don’t say how old she is so naturally tailor anything you tell her to be appropriate for her age group and also ensure you express it as a “good secret” as bearing the weight of an adult’s confidence can be stressful for a child. Expressed in a positive manner that you have chosen to share what you do with her because you think working on herbs, oils, crystals etc. is something you would enjoy doing together might be just the thing to make her feel valued and bring her out of her shell.
Having got her interest you can use the work you do to help her develop skills that will further boost her confidence and social abilities. Try making “shell animals” that you can use to confide your “secret worries and desires to”. Listening to her interaction with her creation may give you a real insight into what is on her mind. Teach her some basic meditation – for a child this will require you helping her to establish some very definite mental images but the two of you could have fun together building a magical place in her mind for her to go if she feels stressed or worried. There can also been a real sense of achievement for a child in craft work. Bottling her own oils, drying her own herbs and flowers, even collecting and labelling her own rocks will give her something tangible at the end of the day to be proud of.
As I am not a mother I’ve sought out a second opinion on this question and the advice given was to encourage the family to work together as a unit. Get all the children to take turns in suggesting activities for you all to do together and make sure they are all involved and nobody is excluded. This will help you find out what interests your middle child and she will feel valued when it is her turn to decide what everybody does. Also as well as looking for things for you and her to do together try and find common interests between her and your other children so she can do things with them too. Give her some responsibility toward the younger child and let her feel grown up by suggesting things her and your elder child can do together.
From a magical perspective I always find that magic with children works best when they are actively involved in it and can understand the purpose of it. I would suggest you sew a small pouch to hold two or three crystals with calming properties (try selenite, celestite and howlite) and give it to your daughter to hold, telling her that whenever she feels sad or unhappy she can take the crystals out of the bag and hold them in her hand. This works with a dual purpose – firstly the crystals do have natural healing properties that will help her but also because it will give you a clear signal that something is on your daughter’s mind and you can take action accordingly. It also has the third benefit of the power of suggestion – tell a child holding a crystal will help them and their own mind will provide additional power to comfort them. The placebo effect seems stronger in children than it is with adults and this effect, combined with the natural healing properties of your chosen crystals should give the boost she needs.