My two year old struggles to sleep... "(?

Ever since she was born my two year old has struggled to sleep, as a baby until about 8 months she refused naps throughout the day and would fall asleep about 8pm ish. It never helped that as a baby her dad would let her sleep in our bed and now hes left us thats left me with the during the night toddles through to my bed from her. Shes now 29 months and does sleep throughout the day for about an hour, but my issue is for some reason she is hating going to bed... she cries and cries and screams and gets in and out of bed, i sit next to her bed reading a magazine not talking to her so im there but not interacting, and it will take me a good hour or so to battle her to sleep. ive tried reading a story, leaving her alone, soft music, more light, less light, new bedding, singing to her, simply ignoring her (other than to put her back into bed) and its like she has a pure fear of her bed. She shares her room with her 7month old sister so naturally wakes her up with all the fuss meaning she cries as shes so tired. My eldest is very sensitive, if people leave the house she cries and im not sure if shes started what seems like a fear of bed because she knows im leaving her when shes asleep. It works similar to this; half 7/8 she gets sleepy, take her to bed, after all the screaming and crying its about 9/10 before im back downstairs, shes up between 5/6am. The problem is when i was pregnant with my second i had severe SPD and struggled alone so some nights when i was in so much pain i couldnt take my eldest back to her bed to sleep and she had the luxury of staying in mummys bed. Im not sure whether to cut her nap during the day out which tends to be about 11ish, or to simply force her each night to bed, or to let her fall asleep downstairs with me and then take her up to avoid all the upset... im at a lose end now being alone to figure this out after my ex introduced the bad habits. Shes very very energetic, she wont sit for long at an activity and is very flitty so winding down with colouring probably wouldnt work. My concern for cutting naps is,that when shes not had a nap before she gets stupid tired between 4/5 and she has to sleep sometimes and then wakes up about 6/7 and then its ridiculous the time shes ready for bed. Her little sister is a beautiful little sleeper,but in 29 months shes had three different homes, three different beds so i know it must be hard. Its just gone from her getting tired, me taking her to bed at about 8ish, within 10 minutes shes sound asleep (this wwas only about 3 months ago) to this.... help! Haha. Sorry to ramble on its just im only 20, their dad left us when i was 12 weeks pregnant with my youngest, im studying a uni degree, so i feel like im losing the plot sometimes with how difficult her sleeping is x