11 month old and a very sudden change in behaviour

[happybunny2014]

This may be a tad rambling but I want to add as much detail as poss:

I have an 11 month old DD, she is on track with everything according to HV. However recently her behaviour has changed with regards to certain things and I wondered is it just a phase or something to keep my eye on...

My best friend who we visit a lot has a 14 month old little boy who has been walking for ages and is very active. Him and DD "play" together as best they can with DD crawling and cruising and him running around. He will bring her toys and sit and share with her, she would follow him around where ever he went and babble at him.

However the past couple of weeks when we've visited DD has gone MENTAL when he goes near her with ANYTHING, she no longer plays with him and if he's running past her she gets very agitated, if he tries to go into the dining room she screams the house down, if we shut the door in the living room she goes mad and screeches and refuses to be comforted at all and will start lunging backwards to get away from me or DH. She also become very distressed with odd things like getting too close to people's feet? Whenever this little lad disappears for a nap or goes out she is completely calm and fine, bar the foot thing.

At home she only ever acts like this in one room which is the strip of landing between all the rooms upstairs. She will crawl out her room, then sit and scream until we remove her from the situation. There are no carpet tacks, or anything that could be causing pain as we did check in case something had hurt her and she was fearful of it.

Needless to say it's left everyone baffled and a tad concerned as to the sudden change. As I recall there haven't been any unpleasant incidents with my DD and this little boy i.e him accidentally whacking her or anything.

Anybody any ideas or suggestions as to what this may be?

It sounds like a phase....attention seeking in a way. I can clearly remember being a baby (I know that sounds odd) but I remember deliberately crawling into a small area by the front door which had a sliding door and then yelling my head off so someone would rescue me. My Mum says I did it in the mornings when she was trying to get my siblings ready.

Is there a pattern to her acting like that on the strip of landing? Are you usually busy doing something else then?

When this little lad comes it's possible she just doesn't like sharing the attention...at her age, she is growing more aware of things like this.

It almost sounds as if she's become very aware of her personal space and doesn't like feeling as if it's invaded or restricted in any way?! It's like she's scared someone is going to step on her or hurt her in some way if they get too close. Does she go to nursery? Just wondering if she's been hurt by another child (as they often are at this age) and it's freaked her out a little? Are your HVs any good? Might be worth asking them for their suggestions!

Thanks LingDiLong I did wonder if it's attention. DD is at home with me at and not been to a nursery yet so I know nothing's come from that.
We're not usually busy when she's out on the landing, we're focused on her and playing. I did think maybe she doesn't like sharing attention with this little lad which is why she screams. The only thing we all noticed for sure is as she begins to scream she looks at the adults in the room which was where my thoughts of attention seeking came in. I'm hoping it is a phase and she'll grow out of it. It may also be like you say, she now knows her own space and doesn't like it suddenly being changed. All in all she's a very happy baby, just the sudden change made me wonder what is going on!
I think a stance of "this too shall pass" is needed haha.
My hv's are okay, stretched thin sometimes so it can take a while to see anyone. May bob to the walk in this week!
Thanks for the suggestions :-)