I apologise for the misunderstanding. Try this - when you arrive home go straight in and totally ignore her. If the kids find this hard explain to them that this is the only way to make the dog feel more secure that you can all look after yourselves. This is harder than it sounds but no eye contact, physical contact or verbal contact until she has given up trying to gain your attention. When she has been relaxed for five minutes you can call her over, get her to sit and reward her. If you cave before that you are giving her the same message that an Alpha expects from the lower ranking members of the pack - an Alpha will ignore the greeting behaviour of lesser ranking animals until it feels that due respect has been shown. It is important to leave the dog for five minutes after it has relaxed to make sure that it really has accepted the situation and is not just thinking about a different approach. Some dogs will go away, think, come back for another go for up to an hour!
When the dog is barking at the gardener simply hold it's collar and move it away from the window or door without saying a word or making eye contact. Move it to another room if needed and leave it until it has stopped barking. As soon as it does allow it back into the room without a word. The dog will realise that you have taken control of the situation and do not need to be protected....although you must be consistent, patient and calm about it. Again this may take some time but watch for subtle changes in the level of barking. No praise until the dog has relaxed for five minutes. You are allowing the dog to realise that it is fine and that as leader it is up to you, not it, what is and is not allowed to be in the yard.
I would stay away from the dog park until you have these behaviours under control and you will find that your dog is much calmer and more relaxed when you do return.